91215618015 has 8 divisors (see below), whose sum is σ = 145944988848. Its totient is φ = 48648329600.

The previous prime is 91215617971. The next prime is 91215618029. The reversal of 91215618015 is 51081651219.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91215618015 - 2¹² = 91215613919 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3040520586 + ... + 3040520615.

It is an arithmetic number, because the mean of its divisors is an integer number (18243123606).

Almost surely, 2^91215618015 is an apocalyptic number.

91215618015 is a deficient number, since it is larger than the sum of its proper divisors (54729370833).

91215618015 is a wasteful number, since it uses less digits than its factorization.

91215618015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6081041209.

The product of its (nonzero) digits is 21600, while the sum is 39.

The spelling of 91215618015 in words is "ninety-one billion, two hundred fifteen million, six hundred eighteen thousand, fifteen".