21665152157 has 8 divisors (see below), whose sum is σ = 23868719712. Its totient is φ = 19500586000.

The previous prime is 21665152141. The next prime is 21665152183. The reversal of 21665152157 is 75125156612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21665152157 - 2⁴ = 21665152141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21665152127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9749183 + ... + 9751404.

It is an arithmetic number, because the mean of its divisors is an integer number (2983589964).

Almost surely, 2^21665152157 is an apocalyptic number.

It is an amenable number.

21665152157 is a deficient number, since it is larger than the sum of its proper divisors (2203567555).

21665152157 is a wasteful number, since it uses less digits than its factorization.

21665152157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19500699.

The product of its digits is 126000, while the sum is 41.

The spelling of 21665152157 in words is "twenty-one billion, six hundred sixty-five million, one hundred fifty-two thousand, one hundred fifty-seven".