21695136657 has 16 divisors (see below), whose sum is σ = 29304483840. Its totient is φ = 14274750672.

The previous prime is 21695136601. The next prime is 21695136667. The reversal of 21695136657 is 75663159612.

It is not a de Polignac number, because 21695136657 - 2¹⁵ = 21695103889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21695136667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 639238 + ... + 672320.

It is an arithmetic number, because the mean of its divisors is an integer number (1831530240).

Almost surely, 2^21695136657 is an apocalyptic number.

It is an amenable number.

21695136657 is a deficient number, since it is larger than the sum of its proper divisors (7609347183).

21695136657 is a wasteful number, since it uses less digits than its factorization.

21695136657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35932.

The product of its digits is 2041200, while the sum is 51.

The spelling of 21695136657 in words is "twenty-one billion, six hundred ninety-five million, one hundred thirty-six thousand, six hundred fifty-seven".