172571978291 has 2 divisors, whose sum is σ = 172571978292. Its totient is φ = 172571978290.

The previous prime is 172571978287. The next prime is 172571978321. The reversal of 172571978291 is 192879175271.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 172571978291 - 2² = 172571978287 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 172571978291.

It is not a weakly prime, because it can be changed into another prime (172571978221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86285989145 + 86285989146.

It is an arithmetic number, because the mean of its divisors is an integer number (86285989146).

Almost surely, 2^172571978291 is an apocalyptic number.

172571978291 is a deficient number, since it is larger than the sum of its proper divisors (1).

172571978291 is an equidigital number, since it uses as much as digits as its factorization.

172571978291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4445280, while the sum is 59.

The spelling of 172571978291 in words is "one hundred seventy-two billion, five hundred seventy-one million, nine hundred seventy-eight thousand, two hundred ninety-one".