21232916640 has 576 divisors, whose sum is σ = 81459302400. Its totient is φ = 5162766336.

The previous prime is 21232916629. The next prime is 21232916669. The reversal of 21232916640 is 4661923212.

It is a happy number.

21232916640 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 2 + 9 + 1 + 6 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21232916595 and 21232916604.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 92720046 + ... + 92720274.

It is an arithmetic number, because the mean of its divisors is an integer number (141422400).

Almost surely, 2^21232916640 is an apocalyptic number.

21232916640 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 21232916640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40729651200).

21232916640 is an abundant number, since it is smaller than the sum of its proper divisors (60226385760).

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

21232916640 is a wasteful number, since it uses less digits than its factorization.

21232916640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 379 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The spelling of 21232916640 in words is "twenty-one billion, two hundred thirty-two million, nine hundred sixteen thousand, six hundred forty".