91515831842 has 18 divisors (see below), whose sum is σ = 145835259633. Its totient is φ = 43062851232.

The previous prime is 91515831821. The next prime is 91515831887. The reversal of 91515831842 is 24813851519.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 83757569281 + 7758262561 = 289409^2 + 88081^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=213911.

It is a super-2 number, since 2×91515831842² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7266683 + ... + 7279265.

Almost surely, 2^91515831842 is an apocalyptic number.

91515831842 is a deficient number, since it is larger than the sum of its proper divisors (54319427791).

91515831842 is an frugal number, since it uses more digits than its factorization.

91515831842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25202 (or 12602 counting only the distinct ones).

The product of its digits is 345600, while the sum is 47.

The spelling of 91515831842 in words is "ninety-one billion, five hundred fifteen million, eight hundred thirty-one thousand, eight hundred forty-two".