21521113036 has 48 divisors (see below), whose sum is σ = 39109150080. Its totient is φ = 10355143680.

The previous prime is 21521112941. The next prime is 21521113049. The reversal of 21521113036 is 63031112512.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21521113036.

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, 4162525 + ... + 4167691.

It is an arithmetic number, because the mean of its divisors is an integer number (814773960).

Almost surely, 2^21521113036 is an apocalyptic number.

It is an amenable number.

21521113036 is a deficient number, since it is larger than the sum of its proper divisors (17588037044).

21521113036 is a wasteful number, since it uses less digits than its factorization.

21521113036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5554 (or 5552 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

Adding to 21521113036 its reverse (63031112512), we get a palindrome (84552225548).

The spelling of 21521113036 in words is "twenty-one billion, five hundred twenty-one million, one hundred thirteen thousand, thirty-six".