213421520 has 40 divisors (see below), whose sum is σ = 534377256. Its totient is φ = 78801408.

The previous prime is 213421511. The next prime is 213421529. The reversal of 213421520 is 25124312.

It is an interprime number because it is at equal distance from previous prime (213421511) and next prime (213421529).

It can be written as a sum of positive squares in 4 ways, for example, as 51724864 + 161696656 = 7192^2 + 12716^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×213421520² = 91097490398220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 213421492 and 213421501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213421529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101567 + ... + 103646.

Almost surely, 2^213421520 is an apocalyptic number.

213421520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213421520 is an abundant number, since it is smaller than the sum of its proper divisors (320955736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

213421520 is a wasteful number, since it uses less digits than its factorization.

213421520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205239 (or 205233 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 213421520 is about 14608.9534190509. The cubic root of 213421520 is about 597.6029548959.

Adding to 213421520 its reverse (25124312), we get a palindrome (238545832).

The spelling of 213421520 in words is "two hundred thirteen million, four hundred twenty-one thousand, five hundred twenty".