917991936 has 120 divisors (see below), whose sum is σ = 2686663980. Its totient is φ = 301694976.

The previous prime is 917991931. The next prime is 917991937. The reversal of 917991936 is 639199719.

It can be written as a sum of positive squares in 2 ways, for example, as 821166336 + 96825600 = 28656^2 + 9840^2 .

It is a super-2 number, since 2×917991936² = 1685418389122056192, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (917991931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 335020 + ... + 337748.

Almost surely, 2^917991936 is an apocalyptic number.

917991936 is a gapful number since it is divisible by the number (96) 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 917991936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1343331990).

917991936 is an abundant number, since it is smaller than the sum of its proper divisors (1768672044).

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

917991936 is a wasteful number, since it uses less digits than its factorization.

917991936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2826 (or 2807 counting only the distinct ones).

The product of its digits is 826686, while the sum is 54.

The square root of 917991936 is about 30298.3817389642. The cubic root of 917991936 is about 971.8806945983.

The spelling of 917991936 in words is "nine hundred seventeen million, nine hundred ninety-one thousand, nine hundred thirty-six".