20831692121 has 2 divisors, whose sum is σ = 20831692122. Its totient is φ = 20831692120.

The previous prime is 20831692111. The next prime is 20831692127. The reversal of 20831692121 is 12129613802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11775505225 + 9056186896 = 108515^2 + 95164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20831692121 is a prime.

It is not a weakly prime, because it can be changed into another prime (20831692127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10415846060 + 10415846061.

It is an arithmetic number, because the mean of its divisors is an integer number (10415846061).

Almost surely, 2^20831692121 is an apocalyptic number.

It is an amenable number.

20831692121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20831692121 is an equidigital number, since it uses as much as digits as its factorization.

20831692121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 35.

The spelling of 20831692121 in words is "twenty billion, eight hundred thirty-one million, six hundred ninety-two thousand, one hundred twenty-one".