191926158431081 has 2 divisors, whose sum is σ = 191926158431082. Its totient is φ = 191926158431080.

The previous prime is 191926158431039. The next prime is 191926158431099. The reversal of 191926158431081 is 180134851629191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181137009451225 + 10789148979856 = 13458715^2 + 3284684^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191926158431081 is a prime.

It is a super-2 number, since 2×191926158431081² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 191926158431081.

It is not a weakly prime, because it can be changed into another prime (191926158431881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95963079215540 + 95963079215541.

It is an arithmetic number, because the mean of its divisors is an integer number (95963079215541).

Almost surely, 2^{191926158431081} is an apocalyptic number.

It is an amenable number.

191926158431081 is a deficient number, since it is larger than the sum of its proper divisors (1).

191926158431081 is an equidigital number, since it uses as much as digits as its factorization.

191926158431081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3732480, while the sum is 59.

The spelling of 191926158431081 in words is "one hundred ninety-one trillion, nine hundred twenty-six billion, one hundred fifty-eight million, four hundred thirty-one thousand, eighty-one".