91990390 has 8 divisors (see below), whose sum is σ = 165582720. Its totient is φ = 36796152.

The previous prime is 91990321. The next prime is 91990411. The reversal of 91990390 is 9309919.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4599510 + ... + 4599529.

It is an arithmetic number, because the mean of its divisors is an integer number (20697840).

Almost surely, 2^91990390 is an apocalyptic number.

91990390 is a deficient number, since it is larger than the sum of its proper divisors (73592330).

91990390 is a wasteful number, since it uses less digits than its factorization.

91990390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9199046.

The product of its (nonzero) digits is 19683, while the sum is 40.

The square root of 91990390 is about 9591.1620776630. The cubic root of 91990390 is about 451.4200245309.

The spelling of 91990390 in words is "ninety-one million, nine hundred ninety thousand, three hundred ninety".