21039685632 has 448 divisors, whose sum is σ = 72473149440. Its totient is φ = 5908267008.

The previous prime is 21039685627. The next prime is 21039685637. The reversal of 21039685632 is 23658693012.

21039685632 is a `hidden beast` number, since 2 + 1 + 0 + 3 + 9 + 6 + 8 + 5 + 632 = 666.

It is an interprime number because it is at equal distance from previous prime (21039685627) and next prime (21039685637).

It is a tau number, because it is divible by the number of its divisors (448).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21039685637) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 165666753 + ... + 165666879.

Almost surely, 2^21039685632 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 21039685632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36236574720).

21039685632 is an abundant number, since it is smaller than the sum of its proper divisors (51433463808).

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

21039685632 is a wasteful number, since it uses less digits than its factorization.

21039685632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 21039685632 in words is "twenty-one billion, thirty-nine million, six hundred eighty-five thousand, six hundred thirty-two".