20831938957 has 2 divisors, whose sum is σ = 20831938958. Its totient is φ = 20831938956.

The previous prime is 20831938943. The next prime is 20831938969. The reversal of 20831938957 is 75983913802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19204139241 + 1627799716 = 138579^2 + 40346^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20831938957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20831938898 and 20831938907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20831938927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10415969478 + 10415969479.

It is an arithmetic number, because the mean of its divisors is an integer number (10415969479).

Almost surely, 2^20831938957 is an apocalyptic number.

It is an amenable number.

20831938957 is a deficient number, since it is larger than the sum of its proper divisors (1).

20831938957 is an equidigital number, since it uses as much as digits as its factorization.

20831938957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3265920, while the sum is 55.

The spelling of 20831938957 in words is "twenty billion, eight hundred thirty-one million, nine hundred thirty-eight thousand, nine hundred fifty-seven".