90172240 has 20 divisors (see below), whose sum is σ = 209650644. Its totient is φ = 36068864.

The previous prime is 90172193. The next prime is 90172253. The reversal of 90172240 is 4227109.

It can be written as a sum of positive squares in 2 ways, for example, as 61528336 + 28643904 = 7844^2 + 5352^2 .

It is a tau number, because it is divible by the number of its divisors (20).

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, 563497 + ... + 563656.

Almost surely, 2^90172240 is an apocalyptic number.

It is an amenable number.

90172240 is an abundant number, since it is smaller than the sum of its proper divisors (119478404).

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

90172240 is a wasteful number, since it uses less digits than its factorization.

90172240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1127166 (or 1127160 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 90172240 is about 9495.9064864814. The cubic root of 90172240 is about 448.4261729061.

Adding to 90172240 its reverse (4227109), we get a palindrome (94399349).

The spelling of 90172240 in words is "ninety million, one hundred seventy-two thousand, two hundred forty".