21380507620 has 24 divisors (see below), whose sum is σ = 45111866688. Its totient is φ = 8511669600.

The previous prime is 21380507527. The next prime is 21380507633. The reversal of 21380507620 is 2670508312.

It is a happy number.

It is a super-2 number, since 2×21380507620² (a number of 21 digits) contains 22 as substring.

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, 2529016 + ... + 2537455.

It is an arithmetic number, because the mean of its divisors is an integer number (1879661112).

Almost surely, 2^21380507620 is an apocalyptic number.

21380507620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21380507620 is an abundant number, since it is smaller than the sum of its proper divisors (23731359068).

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

21380507620 is a wasteful number, since it uses less digits than its factorization.

21380507620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5066691 (or 5066689 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The spelling of 21380507620 in words is "twenty-one billion, three hundred eighty million, five hundred seven thousand, six hundred twenty".