21423688944 has 320 divisors, whose sum is σ = 68224204800. Its totient is φ = 5657693184.

The previous prime is 21423688931. The next prime is 21423688967. The reversal of 21423688944 is 44988632412.

It is a congruent number.

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, 53963754 + ... + 53964150.

It is an arithmetic number, because the mean of its divisors is an integer number (213200640).

Almost surely, 2^21423688944 is an apocalyptic number.

21423688944 is a gapful number since it is divisible by the number (24) 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 21423688944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34112102400).

21423688944 is an abundant number, since it is smaller than the sum of its proper divisors (46800515856).

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

21423688944 is a wasteful number, since it uses less digits than its factorization.

21423688944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620 (or 614 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 51.

The spelling of 21423688944 in words is "twenty-one billion, four hundred twenty-three million, six hundred eighty-eight thousand, nine hundred forty-four".