90421840 has 20 divisors (see below), whose sum is σ = 210230964. Its totient is φ = 36168704.

The previous prime is 90421829. The next prime is 90421853. The reversal of 90421840 is 4812409.

It can be written as a sum of positive squares in 2 ways, for example, as 25522704 + 64899136 = 5052^2 + 8056^2 .

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

It is a super-2 number, since 2×90421840² = 16352218297971200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 90421799 and 90421808.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 565057 + ... + 565216.

Almost surely, 2^90421840 is an apocalyptic number.

It is an amenable number.

90421840 is an abundant number, since it is smaller than the sum of its proper divisors (119809124).

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

90421840 is a wasteful number, since it uses less digits than its factorization.

90421840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1130286 (or 1130280 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 90421840 is about 9509.0399094756. The cubic root of 90421840 is about 448.8395449833.

The spelling of 90421840 in words is "ninety million, four hundred twenty-one thousand, eight hundred forty".