21634830 has 64 divisors (see below), whose sum is σ = 65940480. Its totient is φ = 4944672.

The previous prime is 21634813. The next prime is 21634849. The reversal of 21634830 is 3843612.

It is a happy number.

21634830 is a `hidden beast` number, since 21 + 634 + 8 + 3 + 0 = 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 = 21634794 and 21634803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3834 + ... + 7613.

It is an arithmetic number, because the mean of its divisors is an integer number (1030320).

Almost surely, 2^21634830 is an apocalyptic number.

21634830 is an abundant number, since it is smaller than the sum of its proper divisors (44305650).

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

21634830 is a wasteful number, since it uses less digits than its factorization.

21634830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11470 (or 11464 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21634830 is about 4651.3256174987. The cubic root of 21634830 is about 278.6449408696.

The spelling of 21634830 in words is "twenty-one million, six hundred thirty-four thousand, eight hundred thirty".