21307235328 has 616 divisors, whose sum is σ = 71524276128. Its totient is φ = 6306398208.

The previous prime is 21307235321. The next prime is 21307235329. The reversal of 21307235328 is 82353270312.

21307235328 is a `hidden beast` number, since 2 + 1 + 307 + 23 + 5 + 328 = 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 = 21307235292 and 21307235301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21307235321) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 291879900 + ... + 291879972.

Almost surely, 2^21307235328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21307235328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35762138064).

21307235328 is an abundant number, since it is smaller than the sum of its proper divisors (50217040800).

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

21307235328 is an equidigital number, since it uses as much as digits as its factorization.

21307235328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The spelling of 21307235328 in words is "twenty-one billion, three hundred seven million, two hundred thirty-five thousand, three hundred twenty-eight".