21521122336 has 48 divisors (see below), whose sum is σ = 49336185024. Its totient is φ = 9049307904.

The previous prime is 21521122309. The next prime is 21521122351. The reversal of 21521122336 is 63322112512.

It is a Harshad number since it is a multiple of its sum of digits (28).

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, 894510 + ... + 918253.

It is an arithmetic number, because the mean of its divisors is an integer number (1027837188).

Almost surely, 2^21521122336 is an apocalyptic number.

It is an amenable number.

21521122336 is an abundant number, since it is smaller than the sum of its proper divisors (27815062688).

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

21521122336 is a wasteful number, since it uses less digits than its factorization.

21521122336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1812833 (or 1812825 counting only the distinct ones).

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

Adding to 21521122336 its reverse (63322112512), we get a palindrome (84843234848).

The spelling of 21521122336 in words is "twenty-one billion, five hundred twenty-one million, one hundred twenty-two thousand, three hundred thirty-six".