90728387 has 4 divisors (see below), whose sum is σ = 91390776. Its totient is φ = 90066000.

The previous prime is 90728383. The next prime is 90728441. The reversal of 90728387 is 78382709.

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 90728387 - 2² = 90728383 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90728381) 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, 330989 + ... + 331262.

It is an arithmetic number, because the mean of its divisors is an integer number (22847694).

Almost surely, 2^90728387 is an apocalyptic number.

90728387 is a deficient number, since it is larger than the sum of its proper divisors (662389).

90728387 is a wasteful number, since it uses less digits than its factorization.

90728387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662388.

The product of its (nonzero) digits is 169344, while the sum is 44.

The square root of 90728387 is about 9525.1449857732. The cubic root of 90728387 is about 449.3461896258.

The spelling of 90728387 in words is "ninety million, seven hundred twenty-eight thousand, three hundred eighty-seven".