21807630 has 160 divisors (see below), whose sum is σ = 67082400. Its totient is φ = 5038848.

The previous prime is 21807593. The next prime is 21807647. The reversal of 21807630 is 3670812.

21807630 is a `hidden beast` number, since 21 + 8 + 0 + 7 + 630 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21807594 and 21807603.

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, 200016 + ... + 200124.

It is an arithmetic number, because the mean of its divisors is an integer number (419265).

Almost surely, 2^21807630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21807630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33541200).

21807630 is an abundant number, since it is smaller than the sum of its proper divisors (45274770).

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

21807630 is a wasteful number, since it uses less digits than its factorization.

21807630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21807630 is about 4669.8640237163. The cubic root of 21807630 is about 279.3848314184.

The spelling of 21807630 in words is "twenty-one million, eight hundred seven thousand, six hundred thirty".