21329904960 has 560 divisors, whose sum is σ = 93393987456. Its totient is φ = 4499877888.

The previous prime is 21329904941. The next prime is 21329904977. The reversal of 21329904960 is 6940992312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (560).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2354199 + ... + 2363241.

Almost surely, 2^21329904960 is an apocalyptic number.

21329904960 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 21329904960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46696993728).

21329904960 is an abundant number, since it is smaller than the sum of its proper divisors (72064082496).

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

21329904960 is a wasteful number, since it uses less digits than its factorization.

21329904960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9092 (or 9073 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The spelling of 21329904960 in words is "twenty-one billion, three hundred twenty-nine million, nine hundred four thousand, nine hundred sixty".