91421864 has 16 divisors (see below), whose sum is σ = 171522420. Its totient is φ = 45682560.

The previous prime is 91421861. The next prime is 91421879. The reversal of 91421864 is 46812419.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 91049764 + 372100 = 9542^2 + 610^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (91421861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17474 + ... + 22094.

Almost surely, 2^91421864 is an apocalyptic number.

It is an amenable number.

91421864 is a deficient number, since it is larger than the sum of its proper divisors (80100556).

91421864 is a wasteful number, since it uses less digits than its factorization.

91421864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7100 (or 7096 counting only the distinct ones).

The product of its digits is 13824, while the sum is 35.

The square root of 91421864 is about 9561.4781284067. The cubic root of 91421864 is about 450.4881353267.

The spelling of 91421864 in words is "ninety-one million, four hundred twenty-one thousand, eight hundred sixty-four".