21202115520 has 56 divisors (see below), whose sum is σ = 67316719824. Its totient is φ = 5653897216.

The previous prime is 21202115497. The next prime is 21202115531. The reversal of 21202115520 is 2551120212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11041809 + ... + 11043728.

Almost surely, 2^21202115520 is an apocalyptic number.

21202115520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202115520 is an abundant number, since it is smaller than the sum of its proper divisors (46114604304).

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

21202115520 is a wasteful number, since it uses less digits than its factorization.

21202115520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22085557 (or 22085547 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 21.

Adding to 21202115520 its reverse (2551120212), we get a palindrome (23753235732).

The spelling of 21202115520 in words is "twenty-one billion, two hundred two million, one hundred fifteen thousand, five hundred twenty".