21341520 has 60 divisors (see below), whose sum is σ = 71674356. Its totient is φ = 5690880.

The previous prime is 21341501. The next prime is 21341527. The reversal of 21341520 is 2514312.

It can be written as a sum of positive squares in 2 ways, for example, as 14930496 + 6411024 = 3864^2 + 2532^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21341493 and 21341502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21341527) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14101 + ... + 15540.

Almost surely, 2^21341520 is an apocalyptic number.

21341520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21341520 is an abundant number, since it is smaller than the sum of its proper divisors (50332836).

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

21341520 is a wasteful number, since it uses less digits than its factorization.

21341520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29660 (or 29651 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21341520 is about 4619.6883011736. The cubic root of 21341520 is about 277.3799821883.

Adding to 21341520 its reverse (2514312), we get a palindrome (23855832).

The spelling of 21341520 in words is "twenty-one million, three hundred forty-one thousand, five hundred twenty".