20491764129 has 16 divisors (see below), whose sum is σ = 30360407040. Its totient is φ = 13660169040.

The previous prime is 20491764089. The next prime is 20491764151. The reversal of 20491764129 is 92146719402.

20491764129 is a `hidden beast` number, since 20 + 49 + 176 + 412 + 9 = 666.

It is not a de Polignac number, because 20491764129 - 2⁷ = 20491764001 is a prime.

It is a super-2 number, since 2×20491764129² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20491764229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 607744 + ... + 640574.

It is an arithmetic number, because the mean of its divisors is an integer number (1897525440).

Almost surely, 2^20491764129 is an apocalyptic number.

It is an amenable number.

20491764129 is a deficient number, since it is larger than the sum of its proper divisors (9868642911).

20491764129 is a wasteful number, since it uses less digits than its factorization.

20491764129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55957 (or 55951 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 20491764129 in words is "twenty billion, four hundred ninety-one million, seven hundred sixty-four thousand, one hundred twenty-nine".