91439075 has 24 divisors (see below), whose sum is σ = 139553568. Its totient is φ = 57876480.

The previous prime is 91439071. The next prime is 91439083. The reversal of 91439075 is 57093419.

It is a happy number.

It is not a de Polignac number, because 91439075 - 2² = 91439071 is a prime.

It is a super-2 number, since 2×91439075² = 16722208873711250, which contains 22 as substring.

It is a Smith number, since the sum of its digits (38) 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 (91439071) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17822 + ... + 22371.

It is an arithmetic number, because the mean of its divisors is an integer number (5814732).

Almost surely, 2^91439075 is an apocalyptic number.

91439075 is a deficient number, since it is larger than the sum of its proper divisors (48114493).

91439075 is a wasteful number, since it uses less digits than its factorization.

91439075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40223 (or 40218 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 91439075 is about 9562.3781037982. The cubic root of 91439075 is about 450.5164030534.

The spelling of 91439075 in words is "ninety-one million, four hundred thirty-nine thousand, seventy-five".