21156501696 has 112 divisors (see below), whose sum is σ = 61335757440. Its totient is φ = 6382673920.

The previous prime is 21156501679. The next prime is 21156501697. The reversal of 21156501696 is 69610565112.

It is not an unprimeable number, because it can be changed into a prime (21156501697) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 457360 + ... + 501488.

Almost surely, 2^21156501696 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21156501696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30667878720).

21156501696 is an abundant number, since it is smaller than the sum of its proper divisors (40179255744).

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

21156501696 is a wasteful number, since it uses less digits than its factorization.

21156501696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44382 (or 44372 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 42.

It can be divided in two parts, 211565016 and 96, that added together give a palindrome (211565112).

The spelling of 21156501696 in words is "twenty-one billion, one hundred fifty-six million, five hundred one thousand, six hundred ninety-six".