21165163357 has 12 divisors (see below), whose sum is σ = 22943925120. Its totient is φ = 19515392208.

The previous prime is 21165163333. The next prime is 21165163367. The reversal of 21165163357 is 75336156112.

It is a de Polignac number, because none of the positive numbers 2^k-21165163357 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 (21165163367) 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, 84244 + ... + 222322.

It is an arithmetic number, because the mean of its divisors is an integer number (1911993760).

Almost surely, 2^21165163357 is an apocalyptic number.

It is an amenable number.

21165163357 is a deficient number, since it is larger than the sum of its proper divisors (1778761763).

21165163357 is a wasteful number, since it uses less digits than its factorization.

21165163357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139012 (or 138999 counting only the distinct ones).

The product of its digits is 113400, while the sum is 40.

The spelling of 21165163357 in words is "twenty-one billion, one hundred sixty-five million, one hundred sixty-three thousand, three hundred fifty-seven".