21270323165 has 32 divisors (see below), whose sum is σ = 31469464320. Its totient is φ = 13439913984.

The previous prime is 21270323161. The next prime is 21270323183. The reversal of 21270323165 is 56132307212.

It is not a de Polignac number, because 21270323165 - 2² = 21270323161 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21270323161) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 222026 + ... + 303044.

It is an arithmetic number, because the mean of its divisors is an integer number (983420760).

Almost surely, 2^21270323165 is an apocalyptic number.

It is an amenable number.

21270323165 is a deficient number, since it is larger than the sum of its proper divisors (10199141155).

21270323165 is a wasteful number, since it uses less digits than its factorization.

21270323165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81621.

The product of its (nonzero) digits is 15120, while the sum is 32.

The spelling of 21270323165 in words is "twenty-one billion, two hundred seventy million, three hundred twenty-three thousand, one hundred sixty-five".