191556736993 has 2 divisors, whose sum is σ = 191556736994. Its totient is φ = 191556736992.

The previous prime is 191556736951. The next prime is 191556736999. The reversal of 191556736993 is 399637655191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150115177809 + 41441559184 = 387447^2 + 203572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191556736993 is a prime.

It is not a weakly prime, because it can be changed into another prime (191556736999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95778368496 + 95778368497.

It is an arithmetic number, because the mean of its divisors is an integer number (95778368497).

Almost surely, 2^191556736993 is an apocalyptic number.

It is an amenable number.

191556736993 is a deficient number, since it is larger than the sum of its proper divisors (1).

191556736993 is an equidigital number, since it uses as much as digits as its factorization.

191556736993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41334300, while the sum is 64.

The spelling of 191556736993 in words is "one hundred ninety-one billion, five hundred fifty-six million, seven hundred thirty-six thousand, nine hundred ninety-three".