91215618029 has 2 divisors, whose sum is σ = 91215618030. Its totient is φ = 91215618028.

The previous prime is 91215617971. The next prime is 91215618059. The reversal of 91215618029 is 92081651219.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77674804804 + 13540813225 = 278702^2 + 116365^2 .

It is a cyclic number.

It is not a de Polignac number, because 91215618029 - 2²⁴ = 91198840813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91215618059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45607809014 + 45607809015.

It is an arithmetic number, because the mean of its divisors is an integer number (45607809015).

Almost surely, 2^91215618029 is an apocalyptic number.

It is an amenable number.

91215618029 is a deficient number, since it is larger than the sum of its proper divisors (1).

91215618029 is an equidigital number, since it uses as much as digits as its factorization.

91215618029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 44.

The spelling of 91215618029 in words is "ninety-one billion, two hundred fifteen million, six hundred eighteen thousand, twenty-nine".