91890201 has 12 divisors (see below), whose sum is σ = 132670608. Its totient is φ = 56547504.

The previous prime is 91890191. The next prime is 91890229. The reversal of 91890201 is 10209819.

It is not a de Polignac number, because 91890201 - 2¹³ = 91882009 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91890901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90115 + ... + 91128.

It is an arithmetic number, because the mean of its divisors is an integer number (11055884).

Almost surely, 2^91890201 is an apocalyptic number.

It is an amenable number.

91890201 is a deficient number, since it is larger than the sum of its proper divisors (40780407).

91890201 is a wasteful number, since it uses less digits than its factorization.

91890201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181272 (or 181259 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 91890201 is about 9585.9376693154. The cubic root of 91890201 is about 451.2560807748.

It can be divided in two parts, 918 and 90201, that added together give a palindrome (91119).

The spelling of 91890201 in words is "ninety-one million, eight hundred ninety thousand, two hundred one".