213122320 has 20 divisors (see below), whose sum is σ = 495509580. Its totient is φ = 85248896.

The previous prime is 213122317. The next prime is 213122321. The reversal of 213122320 is 23221312.

It can be written as a sum of positive squares in 2 ways, for example, as 156150016 + 56972304 = 12496^2 + 7548^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×213122320² = 90842246564364800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 213122294 and 213122303.

It is not an unprimeable number, because it can be changed into a prime (213122321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1331935 + ... + 1332094.

It is an arithmetic number, because the mean of its divisors is an integer number (24775479).

Almost surely, 2^213122320 is an apocalyptic number.

213122320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213122320 is an abundant number, since it is smaller than the sum of its proper divisors (282387260).

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

213122320 is a wasteful number, since it uses less digits than its factorization.

213122320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2664042 (or 2664036 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 213122320 is about 14598.7095320100. The cubic root of 213122320 is about 597.3235603515.

Adding to 213122320 its reverse (23221312), we get a palindrome (236343632).

It can be divided in two parts, 21312 and 2320, that added together give a palindrome (23632).

The spelling of 213122320 in words is "two hundred thirteen million, one hundred twenty-two thousand, three hundred twenty".