81235015177 has 2 divisors, whose sum is σ = 81235015178. Its totient is φ = 81235015176.

The previous prime is 81235015159. The next prime is 81235015193. The reversal of 81235015177 is 77151053218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54149755401 + 27085259776 = 232701^2 + 164576^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81235015177 is a prime.

It is not a weakly prime, because it can be changed into another prime (81235010177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40617507588 + 40617507589.

It is an arithmetic number, because the mean of its divisors is an integer number (40617507589).

Almost surely, 2^81235015177 is an apocalyptic number.

It is an amenable number.

81235015177 is a deficient number, since it is larger than the sum of its proper divisors (1).

81235015177 is an equidigital number, since it uses as much as digits as its factorization.

81235015177 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58800, while the sum is 40.

The spelling of 81235015177 in words is "eighty-one billion, two hundred thirty-five million, fifteen thousand, one hundred seventy-seven".