21371634 has 32 divisors (see below), whose sum is σ = 47825280. Its totient is φ = 7074000.

The previous prime is 21371627. The next prime is 21371653. The reversal of 21371634 is 43617312.

21371634 is a `hidden beast` number, since 21 + 3 + 7 + 1 + 634 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21371598 and 21371607.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6844 + ... + 9464.

It is an arithmetic number, because the mean of its divisors is an integer number (1494540).

Almost surely, 2^21371634 is an apocalyptic number.

21371634 is an abundant number, since it is smaller than the sum of its proper divisors (26453646).

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

21371634 is a wasteful number, since it uses less digits than its factorization.

21371634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2783 (or 2777 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 21371634 is about 4622.9464630255. The cubic root of 21371634 is about 277.5103867551.

Adding to 21371634 its reverse (43617312), we get a palindrome (64988946).

The spelling of 21371634 in words is "twenty-one million, three hundred seventy-one thousand, six hundred thirty-four".