21939755040 has 384 divisors, whose sum is σ = 88004689920. Its totient is φ = 5000776704.

The previous prime is 21939755021. The next prime is 21939755051. The reversal of 21939755040 is 4055793912.

It is a happy number.

21939755040 is a `hidden beast` number, since 2 + 1 + 9 + 3 + 97 + 550 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14000337 + ... + 14001903.

It is an arithmetic number, because the mean of its divisors is an integer number (229178880).

Almost surely, 2^21939755040 is an apocalyptic number.

21939755040 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 21939755040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44002344960).

21939755040 is an abundant number, since it is smaller than the sum of its proper divisors (66064934880).

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

21939755040 is a wasteful number, since it uses less digits than its factorization.

21939755040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2061 (or 2047 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The spelling of 21939755040 in words is "twenty-one billion, nine hundred thirty-nine million, seven hundred fifty-five thousand, forty".