21442423040 has 72 divisors (see below), whose sum is σ = 51431132088. Its totient is φ = 8565309440.

The previous prime is 21442423033. The next prime is 21442423061. The reversal of 21442423040 is 4032424412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 60964864 + 21381458176 = 7808^2 + 146224^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 963074 + ... + 985086.

It is an arithmetic number, because the mean of its divisors is an integer number (714321279).

Almost surely, 2^21442423040 is an apocalyptic number.

21442423040 is a gapful number since it is divisible by the number (20) 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 21442423040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25715566044).

21442423040 is an abundant number, since it is smaller than the sum of its proper divisors (29988709048).

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

21442423040 is an equidigital number, since it uses as much as digits as its factorization.

21442423040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22795 (or 22781 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21442423040 its reverse (4032424412), we get a palindrome (25474847452).

The spelling of 21442423040 in words is "twenty-one billion, four hundred forty-two million, four hundred twenty-three thousand, forty".