91663940 has 12 divisors (see below), whose sum is σ = 192494316. Its totient is φ = 36665568.

The previous prime is 91663939. The next prime is 91663963. The reversal of 91663940 is 4936619.

It can be written as a sum of positive squares in 2 ways, for example, as 67141636 + 24522304 = 8194^2 + 4952^2 .

It is a junction number, because it is equal to n+sod(n) for n = 91663894 and 91663903.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2291579 + ... + 2291618.

It is an arithmetic number, because the mean of its divisors is an integer number (16041193).

Almost surely, 2^91663940 is an apocalyptic number.

It is an amenable number.

91663940 is an abundant number, since it is smaller than the sum of its proper divisors (100830376).

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

91663940 is a wasteful number, since it uses less digits than its factorization.

91663940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4583206 (or 4583204 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 91663940 is about 9574.1286809819. The cubic root of 91663940 is about 450.8854008135.

The spelling of 91663940 in words is "ninety-one million, six hundred sixty-three thousand, nine hundred forty".