21413520 has 60 divisors (see below), whose sum is σ = 71916156. Its totient is φ = 5710080.

The previous prime is 21413479. The next prime is 21413531. The reversal of 21413520 is 2531412.

21413520 is a `hidden beast` number, since 2 + 141 + 3 + 520 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13927824 + 7485696 = 3732^2 + 2736^2 .

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 = 21413493 and 21413502.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14151 + ... + 15590.

Almost surely, 2^21413520 is an apocalyptic number.

21413520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21413520 is an abundant number, since it is smaller than the sum of its proper divisors (50502636).

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

21413520 is a wasteful number, since it uses less digits than its factorization.

21413520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29760 (or 29751 counting only the distinct ones).

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

The square root of 21413520 is about 4627.4744731873. The cubic root of 21413520 is about 277.6915648303.

Adding to 21413520 its reverse (2531412), we get a palindrome (23944932).

The spelling of 21413520 in words is "twenty-one million, four hundred thirteen thousand, five hundred twenty".