90421440 has 112 divisors (see below), whose sum is σ = 289681920. Its totient is φ = 23895040.

The previous prime is 90421439. The next prime is 90421447. The reversal of 90421440 is 4412409.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 90421440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90421447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125401 + ... + 126119.

Almost surely, 2^90421440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144840960).

90421440 is an abundant number, since it is smaller than the sum of its proper divisors (199260480).

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

90421440 is a wasteful number, since it uses less digits than its factorization.

90421440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870 (or 860 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 90421440 is about 9509.0188768348. The cubic root of 90421440 is about 448.8388831370.

Adding to 90421440 its reverse (4412409), we get a palindrome (94833849).

The spelling of 90421440 in words is "ninety million, four hundred twenty-one thousand, four hundred forty".