20644722291 has 32 divisors (see below), whose sum is σ = 28147691520. Its totient is φ = 13456656000.

The previous prime is 20644722247. The next prime is 20644722299. The reversal of 20644722291 is 19222744602.

It is not a de Polignac number, because 20644722291 - 2¹⁸ = 20644460147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20644722299) 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 31 ways as a sum of consecutive naturals, for example, 14948421 + ... + 14949801.

It is an arithmetic number, because the mean of its divisors is an integer number (879615360).

Almost surely, 2^20644722291 is an apocalyptic number.

20644722291 is a deficient number, since it is larger than the sum of its proper divisors (7502969229).

20644722291 is a wasteful number, since it uses less digits than its factorization.

20644722291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2067.

The product of its (nonzero) digits is 96768, while the sum is 39.

The spelling of 20644722291 in words is "twenty billion, six hundred forty-four million, seven hundred twenty-two thousand, two hundred ninety-one".