20920618757 has 2 divisors, whose sum is σ = 20920618758. Its totient is φ = 20920618756.

The previous prime is 20920618721. The next prime is 20920618799. The reversal of 20920618757 is 75781602902.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16618045921 + 4302572836 = 128911^2 + 65594^2 .

It is a cyclic number.

It is not a de Polignac number, because 20920618757 - 2¹² = 20920614661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20920618717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10460309378 + 10460309379.

It is an arithmetic number, because the mean of its divisors is an integer number (10460309379).

Almost surely, 2^20920618757 is an apocalyptic number.

It is an amenable number.

20920618757 is a deficient number, since it is larger than the sum of its proper divisors (1).

20920618757 is an equidigital number, since it uses as much as digits as its factorization.

20920618757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 423360, while the sum is 47.

The spelling of 20920618757 in words is "twenty billion, nine hundred twenty million, six hundred eighteen thousand, seven hundred fifty-seven".