21513026436 has 48 divisors (see below), whose sum is σ = 54788337408. Its totient is φ = 6515776800.

The previous prime is 21513026429. The next prime is 21513026441. The reversal of 21513026436 is 63462031512.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 21513026397 and 21513026406.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 224931 + ... + 305973.

It is an arithmetic number, because the mean of its divisors is an integer number (1141423696).

Almost surely, 2^21513026436 is an apocalyptic number.

It is an amenable number.

21513026436 is an abundant number, since it is smaller than the sum of its proper divisors (33275310972).

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

21513026436 is a wasteful number, since it uses less digits than its factorization.

21513026436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83072 (or 83070 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

Adding to 21513026436 its reverse (63462031512), we get a palindrome (84975057948).

The spelling of 21513026436 in words is "twenty-one billion, five hundred thirteen million, twenty-six thousand, four hundred thirty-six".