90423540 has 60 divisors (see below), whose sum is σ = 283667076. Its totient is φ = 24112512.

The previous prime is 90423521. The next prime is 90423547. The reversal of 90423540 is 4532409.

It can be written as a sum of positive squares in 2 ways, for example, as 68856804 + 21566736 = 8298^2 + 4644^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×90423540² = 16352833172263200, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90423547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 26289 + ... + 29528.

Almost surely, 2^90423540 is an apocalyptic number.

90423540 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

90423540 is an abundant number, since it is smaller than the sum of its proper divisors (193243536).

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

90423540 is a wasteful number, since it uses less digits than its factorization.

90423540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55838 (or 55827 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 90423540 is about 9509.1292976802. The cubic root of 90423540 is about 448.8423578083.

Adding to 90423540 its reverse (4532409), we get a palindrome (94955949).

The spelling of 90423540 in words is "ninety million, four hundred twenty-three thousand, five hundred forty".