90125640 has 144 divisors (see below), whose sum is σ = 322112700. Its totient is φ = 21838080.

The previous prime is 90125621. The next prime is 90125641. The reversal of 90125640 is 4652109.

90125640 is a `hidden beast` number, since 9 + 0 + 12 + 5 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 84162276 + 5963364 = 9174^2 + 2442^2 .

It is not an unprimeable number, because it can be changed into a prime (90125641) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 42526 + ... + 44594.

Almost surely, 2^90125640 is an apocalyptic number.

90125640 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90125640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161056350).

90125640 is an abundant number, since it is smaller than the sum of its proper divisors (231987060).

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

90125640 is a wasteful number, since it uses less digits than its factorization.

90125640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2108 (or 2090 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 90125640 is about 9493.4524805257. The cubic root of 90125640 is about 448.3489123936.

Adding to 90125640 its reverse (4652109), we get a palindrome (94777749).

The spelling of 90125640 in words is "ninety million, one hundred twenty-five thousand, six hundred forty".