21165165606057 has 48 divisors (see below), whose sum is σ = 31323908913024. Its totient is φ = 12701280556800.

The previous prime is 21165165606037. The next prime is 21165165606073. The reversal of 21165165606057 is 75060656156112.

It is not a de Polignac number, because 21165165606057 - 2¹⁸ = 21165165343913 is a prime.

It is a super-2 number, since 2×21165165606057² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21165165606007) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 353707413 + ... + 353767245.

It is an arithmetic number, because the mean of its divisors is an integer number (652581435688).

Almost surely, 2^{21165165606057} is an apocalyptic number.

It is an amenable number.

21165165606057 is a deficient number, since it is larger than the sum of its proper divisors (10158743306967).

21165165606057 is a wasteful number, since it uses less digits than its factorization.

21165165606057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69422 (or 69411 counting only the distinct ones).

The product of its (nonzero) digits is 2268000, while the sum is 51.

The spelling of 21165165606057 in words is "twenty-one trillion, one hundred sixty-five billion, one hundred sixty-five million, six hundred six thousand, fifty-seven".