90102491 has 4 divisors (see below), whose sum is σ = 91802592. Its totient is φ = 88402392.

The previous prime is 90102487. The next prime is 90102497. The reversal of 90102491 is 19420109.

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 90102491 - 2² = 90102487 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 90102491.

It is not an unprimeable number, because it can be changed into a prime (90102497) 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, 849971 + ... + 850076.

It is an arithmetic number, because the mean of its divisors is an integer number (22950648).

Almost surely, 2^90102491 is an apocalyptic number.

90102491 is a deficient number, since it is larger than the sum of its proper divisors (1700101).

90102491 is a wasteful number, since it uses less digits than its factorization.

90102491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1700100.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 90102491 is about 9492.2331935114. The cubic root of 90102491 is about 448.3105225869.

The spelling of 90102491 in words is "ninety million, one hundred two thousand, four hundred ninety-one".