91679777280 has 960 divisors, whose sum is σ = 396799603200. Its totient is φ = 19046596608.

The previous prime is 91679777251. The next prime is 91679777281. The reversal of 91679777280 is 8277797619.

It is a tau number, because it is divible by the number of its divisors (960).

It is a super-2 number, since 2×91679777280² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (91679777281) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 153054421 + ... + 153055019.

It is an arithmetic number, because the mean of its divisors is an integer number (413332920).

Almost surely, 2^91679777280 is an apocalyptic number.

91679777280 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91679777280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198399801600).

91679777280 is an abundant number, since it is smaller than the sum of its proper divisors (305119825920).

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

91679777280 is a wasteful number, since it uses less digits than its factorization.

91679777280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721 (or 702 counting only the distinct ones).

The product of its (nonzero) digits is 18670176, while the sum is 63.

The spelling of 91679777280 in words is "ninety-one billion, six hundred seventy-nine million, seven hundred seventy-seven thousand, two hundred eighty".