91999994 has 4 divisors (see below), whose sum is σ = 137999994. Its totient is φ = 45999996.

The previous prime is 91999993. The next prime is 92000011. The reversal of 91999994 is 49999919.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49999919 = 2113 ⋅23663.

It can be written as a sum of positive squares in only one way, i.e., 65011969 + 26988025 = 8063^2 + 5195^2 .

It is not an unprimeable number, because it can be changed into a prime (91999993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22999997 + ... + 23000000.

Almost surely, 2^91999994 is an apocalyptic number.

91999994 is a deficient number, since it is larger than the sum of its proper divisors (46000000).

91999994 is a wasteful number, since it uses less digits than its factorization.

91999994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45999999.

The product of its digits is 2125764, while the sum is 59.

The square root of 91999994 is about 9591.6627338538. The cubic root of 91999994 is about 451.4357337336.

The spelling of 91999994 in words is "ninety-one million, nine hundred ninety-nine thousand, nine hundred ninety-four".