90728578 has 4 divisors (see below), whose sum is σ = 136092870. Its totient is φ = 45364288.

The previous prime is 90728563. The next prime is 90728593. The reversal of 90728578 is 87582709.

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

It is an interprime number because it is at equal distance from previous prime (90728563) and next prime (90728593).

It can be written as a sum of positive squares in only one way, i.e., 67947049 + 22781529 = 8243^2 + 4773^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22682143 + ... + 22682146.

Almost surely, 2^90728578 is an apocalyptic number.

90728578 is a deficient number, since it is larger than the sum of its proper divisors (45364292).

90728578 is a wasteful number, since it uses less digits than its factorization.

90728578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45364291.

The product of its (nonzero) digits is 282240, while the sum is 46.

The square root of 90728578 is about 9525.1550118620. The cubic root of 90728578 is about 449.3465049445.

The spelling of 90728578 in words is "ninety million, seven hundred twenty-eight thousand, five hundred seventy-eight".