21113463520 has 24 divisors (see below), whose sum is σ = 49880557944. Its totient is φ = 8445385344.

The previous prime is 21113463517. The next prime is 21113463529. The reversal of 21113463520 is 2536431112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113463529) 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, 65979414 + ... + 65979733.

It is an arithmetic number, because the mean of its divisors is an integer number (2078356581).

Almost surely, 2^21113463520 is an apocalyptic number.

21113463520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113463520 is an abundant number, since it is smaller than the sum of its proper divisors (28767094424).

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

21113463520 is a wasteful number, since it uses less digits than its factorization.

21113463520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131959162 (or 131959154 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

Adding to 21113463520 its reverse (2536431112), we get a palindrome (23649894632).

The spelling of 21113463520 in words is "twenty-one billion, one hundred thirteen million, four hundred sixty-three thousand, five hundred twenty".