20901965023957 has 2 divisors, whose sum is σ = 20901965023958. Its totient is φ = 20901965023956.

The previous prime is 20901965023939. The next prime is 20901965023969. The reversal of 20901965023957 is 75932056910902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11610143057956 + 9291821966001 = 3407366^2 + 3048249^2 .

It is a cyclic number.

It is not a de Polignac number, because 20901965023957 - 2¹¹ = 20901965021909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20901965023987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10450982511978 + 10450982511979.

It is an arithmetic number, because the mean of its divisors is an integer number (10450982511979).

Almost surely, 2^{20901965023957} is an apocalyptic number.

It is an amenable number.

20901965023957 is a deficient number, since it is larger than the sum of its proper divisors (1).

20901965023957 is an equidigital number, since it uses as much as digits as its factorization.

20901965023957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9185400, while the sum is 58.

The spelling of 20901965023957 in words is "twenty trillion, nine hundred one billion, nine hundred sixty-five million, twenty-three thousand, nine hundred fifty-seven".