21969668157 has 12 divisors (see below), whose sum is σ = 31117362816. Its totient is φ = 13784889280.

The previous prime is 21969668153. The next prime is 21969668177. The reversal of 21969668157 is 75186696912.

It is not a de Polignac number, because 21969668157 - 2² = 21969668153 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21969668157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21969668153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12669069 + ... + 12670802.

It is an arithmetic number, because the mean of its divisors is an integer number (2593113568).

Almost surely, 2^21969668157 is an apocalyptic number.

It is an amenable number.

21969668157 is a deficient number, since it is larger than the sum of its proper divisors (9147694659).

21969668157 is a wasteful number, since it uses less digits than its factorization.

21969668157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25339908 (or 25339891 counting only the distinct ones).

The product of its digits is 9797760, while the sum is 60.

The spelling of 21969668157 in words is "twenty-one billion, nine hundred sixty-nine million, six hundred sixty-eight thousand, one hundred fifty-seven".