20621240440 has 64 divisors (see below), whose sum is σ = 47551795200. Its totient is φ = 8045860992.

The previous prime is 20621240413. The next prime is 20621240441. The reversal of 20621240440 is 4404212602.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20621240441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 222969 + ... + 301591.

It is an arithmetic number, because the mean of its divisors is an integer number (742996800).

Almost surely, 2^20621240440 is an apocalyptic number.

20621240440 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 20621240440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23775897600).

20621240440 is an abundant number, since it is smaller than the sum of its proper divisors (26930554760).

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

20621240440 is a wasteful number, since it uses less digits than its factorization.

20621240440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78796 (or 78792 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

The spelling of 20621240440 in words is "twenty billion, six hundred twenty-one million, two hundred forty thousand, four hundred forty".