91969878 has 64 divisors (see below), whose sum is σ = 246984192. Its totient is φ = 22049280.

The previous prime is 91969877. The next prime is 91969897. The reversal of 91969878 is 87896919.

It is a super-3 number, since 3×91969878³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91969877) 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, 1651 + ... + 13662.

It is an arithmetic number, because the mean of its divisors is an integer number (3859128).

Almost surely, 2^91969878 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91969878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123492096).

91969878 is an abundant number, since it is smaller than the sum of its proper divisors (155014314).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91969878 is a wasteful number, since it uses less digits than its factorization.

91969878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15349.

The product of its digits is 1959552, while the sum is 57.

The square root of 91969878 is about 9590.0927002819. The cubic root of 91969878 is about 451.3864695191.

It can be divided in two parts, 91 and 969878, that added together give a palindrome (969969).

The spelling of 91969878 in words is "ninety-one million, nine hundred sixty-nine thousand, eight hundred seventy-eight".