21437157696 has 168 divisors, whose sum is σ = 58983628032. Its totient is φ = 6870988800.

The previous prime is 21437157691. The next prime is 21437157719. The reversal of 21437157696 is 69675173412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21437157691) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41145916 + ... + 41146436.

It is an arithmetic number, because the mean of its divisors is an integer number (351093024).

Almost surely, 2^21437157696 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 21437157696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29491814016).

21437157696 is an abundant number, since it is smaller than the sum of its proper divisors (37546470336).

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

21437157696 is a wasteful number, since it uses less digits than its factorization.

21437157696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821 (or 780 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 51.

The spelling of 21437157696 in words is "twenty-one billion, four hundred thirty-seven million, one hundred fifty-seven thousand, six hundred ninety-six".