90720788 has 12 divisors (see below), whose sum is σ = 159353460. Its totient is φ = 45191232.

The previous prime is 90720769. The next prime is 90720793. The reversal of 90720788 is 88702709.

It can be written as a sum of positive squares in 2 ways, for example, as 45535504 + 45185284 = 6748^2 + 6722^2 .

It is a super-2 number, since 2×90720788² = 16460522750681888, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41081 + ... + 43232.

It is an arithmetic number, because the mean of its divisors is an integer number (13279455).

Almost surely, 2^90720788 is an apocalyptic number.

It is an amenable number.

90720788 is a deficient number, since it is larger than the sum of its proper divisors (68632672).

90720788 is a wasteful number, since it uses less digits than its factorization.

90720788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84586 (or 84584 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 90720788 is about 9524.7460858545. The cubic root of 90720788 is about 449.3336442063. Note that the first 3 decimals are identical.

The spelling of 90720788 in words is "ninety million, seven hundred twenty thousand, seven hundred eighty-eight".