91878786901 has 32 divisors (see below), whose sum is σ = 103562219520. Its totient is φ = 80797953600.

The previous prime is 91878786893. The next prime is 91878786907. The reversal of 91878786901 is 10968787819.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 91878786901 - 2³ = 91878786893 is a prime.

It is a super-2 number, since 2×91878786901² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91878786907) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60011506 + ... + 60013036.

It is an arithmetic number, because the mean of its divisors is an integer number (3236319360).

Almost surely, 2^91878786901 is an apocalyptic number.

It is an amenable number.

91878786901 is a deficient number, since it is larger than the sum of its proper divisors (11683432619).

91878786901 is a wasteful number, since it uses less digits than its factorization.

91878786901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2977.

The product of its (nonzero) digits is 12192768, while the sum is 64.

The spelling of 91878786901 in words is "ninety-one billion, eight hundred seventy-eight million, seven hundred eighty-six thousand, nine hundred one".