21521102352 has 20 divisors (see below), whose sum is σ = 55596181200. Its totient is φ = 7173700768.

The previous prime is 21521102347. The next prime is 21521102353. The reversal of 21521102352 is 25320112512.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21521102353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 224178102 + ... + 224178197.

It is an arithmetic number, because the mean of its divisors is an integer number (2779809060).

Almost surely, 2^21521102352 is an apocalyptic number.

It is an amenable number.

21521102352 is an abundant number, since it is smaller than the sum of its proper divisors (34075078848).

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

21521102352 is a wasteful number, since it uses less digits than its factorization.

21521102352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448356310 (or 448356304 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 21521102352 its reverse (25320112512), we get a palindrome (46841214864).

The spelling of 21521102352 in words is "twenty-one billion, five hundred twenty-one million, one hundred two thousand, three hundred fifty-two".