90191866 has 16 divisors (see below), whose sum is σ = 139426560. Its totient is φ = 43724880.

The previous prime is 90191863. The next prime is 90191869. The reversal of 90191866 is 66819109.

It is an interprime number because it is at equal distance from previous prime (90191863) and next prime (90191869).

It is not an unprimeable number, because it can be changed into a prime (90191863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21055 + ... + 24973.

It is an arithmetic number, because the mean of its divisors is an integer number (8714160).

Almost surely, 2^90191866 is an apocalyptic number.

90191866 is a deficient number, since it is larger than the sum of its proper divisors (49234694).

90191866 is a wasteful number, since it uses less digits than its factorization.

90191866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4269.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 90191866 is about 9496.9398229114. The cubic root of 90191866 is about 448.4587038847.

The spelling of 90191866 in words is "ninety million, one hundred ninety-one thousand, eight hundred sixty-six".