21640268755191 has 8 divisors (see below), whose sum is σ = 29073948862464. Its totient is φ = 14316717242360.

The previous prime is 21640268755109. The next prime is 21640268755201. The reversal of 21640268755191 is 19155786204612.

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 21640268755191 - 2¹⁷ = 21640268624119 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21640268754191) 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, 27532148151 + ... + 27532148936.

It is an arithmetic number, because the mean of its divisors is an integer number (3634243607808).

Almost surely, 2^{21640268755191} is an apocalyptic number.

21640268755191 is a deficient number, since it is larger than the sum of its proper divisors (7433680107273).

21640268755191 is a wasteful number, since it uses less digits than its factorization.

21640268755191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55064297221.

The product of its (nonzero) digits is 7257600, while the sum is 57.

The spelling of 21640268755191 in words is "twenty-one trillion, six hundred forty billion, two hundred sixty-eight million, seven hundred fifty-five thousand, one hundred ninety-one".