90191051 has 4 divisors (see below), whose sum is σ = 90262632. Its totient is φ = 90119472.

The previous prime is 90191039. The next prime is 90191093. The reversal of 90191051 is 15019109.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 90191051 - 2²⁶ = 23082187 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 90191051.

It is not an unprimeable number, because it can be changed into a prime (90191551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33866 + ... + 36431.

It is an arithmetic number, because the mean of its divisors is an integer number (22565658).

Almost surely, 2^90191051 is an apocalyptic number.

90191051 is a deficient number, since it is larger than the sum of its proper divisors (71581).

90191051 is a wasteful number, since it uses less digits than its factorization.

90191051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71580.

The product of its (nonzero) digits is 405, while the sum is 26.

The square root of 90191051 is about 9496.8969142557. The cubic root of 90191051 is about 448.4573530795.

The spelling of 90191051 in words is "ninety million, one hundred ninety-one thousand, fifty-one".