90780605 has 6 divisors (see below), whose sum is σ = 108962298. Its totient is φ = 72607440.

The previous prime is 90780593. The next prime is 90780607. The reversal of 90780605 is 50608709.

It can be written as a sum of positive squares in 3 ways, for example, as 57729604 + 33051001 = 7598^2 + 5749^2 .

It is not a de Polignac number, because 90780605 - 2¹⁰ = 90779581 is a prime.

It is a super-2 number, since 2×90780605² = 16482236488332050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90780607) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19175 + ... + 23435.

It is an arithmetic number, because the mean of its divisors is an integer number (18160383).

Almost surely, 2^90780605 is an apocalyptic number.

It is an amenable number.

90780605 is a deficient number, since it is larger than the sum of its proper divisors (18181693).

90780605 is an frugal number, since it uses more digits than its factorization.

90780605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8527 (or 4266 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 90780605 is about 9527.8856521266. The cubic root of 90780605 is about 449.4323789654.

The spelling of 90780605 in words is "ninety million, seven hundred eighty thousand, six hundred five".