91990045 has 16 divisors (see below), whose sum is σ = 128844288. Its totient is φ = 61735680.

The previous prime is 91990007. The next prime is 91990081. The reversal of 91990045 is 54009919.

It is not a de Polignac number, because 91990045 - 2²¹ = 89892893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91989986 and 91990013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26316 + ... + 29605.

It is an arithmetic number, because the mean of its divisors is an integer number (8052768).

Almost surely, 2^91990045 is an apocalyptic number.

It is an amenable number.

91990045 is a deficient number, since it is larger than the sum of its proper divisors (36854243).

91990045 is a wasteful number, since it uses less digits than its factorization.

91990045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55980.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 91990045 is about 9591.1440923385. The cubic root of 91990045 is about 451.4194601962.

The spelling of 91990045 in words is "ninety-one million, nine hundred ninety thousand, forty-five".