90172440 has 96 divisors (see below), whose sum is σ = 303947280. Its totient is φ = 24043392.

The previous prime is 90172427. The next prime is 90172463. The reversal of 90172440 is 4427109.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5082 + ... + 14358.

Almost surely, 2^90172440 is an apocalyptic number.

90172440 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 90172440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151973640).

90172440 is an abundant number, since it is smaller than the sum of its proper divisors (213774840).

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

90172440 is a wasteful number, since it uses less digits than its factorization.

90172440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9303 (or 9287 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 90172440 is about 9495.9170173291. The cubic root of 90172440 is about 448.4265044389.

Adding to 90172440 its reverse (4427109), we get a palindrome (94599549).

The spelling of 90172440 in words is "ninety million, one hundred seventy-two thousand, four hundred forty".