90128780 has 96 divisors (see below), whose sum is σ = 235253760. Its totient is φ = 28304640.

The previous prime is 90128771. The next prime is 90128791. The reversal of 90128780 is 8782109.

90128780 = 3353² + 3354² + ... + 3360².

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 90128780.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 81914 + ... + 83006.

It is an arithmetic number, because the mean of its divisors is an integer number (2450560).

Almost surely, 2^90128780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90128780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117626880).

90128780 is an abundant number, since it is smaller than the sum of its proper divisors (145124980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

90128780 is a wasteful number, since it uses less digits than its factorization.

90128780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1159 (or 1157 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 90128780 is about 9493.6178562232. The cubic root of 90128780 is about 448.3541191962.

The spelling of 90128780 in words is "ninety million, one hundred twenty-eight thousand, seven hundred eighty".