90728819 has 4 divisors (see below), whose sum is σ = 95504040. Its totient is φ = 85953600.

The previous prime is 90728809. The next prime is 90728821. The reversal of 90728819 is 91882709.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91882709 = 1847 ⋅49747.

It is a cyclic number.

It is not a de Polignac number, because 90728819 - 2⁸ = 90728563 is a prime.

It is a super-2 number, since 2×90728819² = 16463437194269522, which contains 22 as substring.

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 90728819.

It is not an unprimeable number, because it can be changed into a prime (90728809) 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, 2387582 + ... + 2387619.

It is an arithmetic number, because the mean of its divisors is an integer number (23876010).

Almost surely, 2^90728819 is an apocalyptic number.

90728819 is a deficient number, since it is larger than the sum of its proper divisors (4775221).

90728819 is a wasteful number, since it uses less digits than its factorization.

90728819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4775220.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 90728819 is about 9525.1676625664. The cubic root of 90728819 is about 449.3469028067.

The spelling of 90728819 in words is "ninety million, seven hundred twenty-eight thousand, eight hundred nineteen".