20631604757 has 4 divisors (see below), whose sum is σ = 20633823756. Its totient is φ = 20629385760.

The previous prime is 20631604703. The next prime is 20631604771. The reversal of 20631604757 is 75740613602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16008828676 + 4622776081 = 126526^2 + 67991^2 .

It is a cyclic number.

It is not a de Polignac number, because 20631604757 - 2¹⁶ = 20631539221 is a prime.

It is a super-2 number, since 2×20631604757² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20631604657) 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 3 ways as a sum of consecutive naturals, for example, 1095494 + ... + 1114167.

It is an arithmetic number, because the mean of its divisors is an integer number (5158455939).

Almost surely, 2^20631604757 is an apocalyptic number.

It is an amenable number.

20631604757 is a deficient number, since it is larger than the sum of its proper divisors (2218999).

20631604757 is an equidigital number, since it uses as much as digits as its factorization.

20631604757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2218998.

The product of its (nonzero) digits is 211680, while the sum is 41.

The spelling of 20631604757 in words is "twenty billion, six hundred thirty-one million, six hundred four thousand, seven hundred fifty-seven".