21674646 has 24 divisors (see below), whose sum is σ = 53670864. Its totient is φ = 6192720.

The previous prime is 21674617. The next prime is 21674659. The reversal of 21674646 is 64647612.

21674646 is a `hidden beast` number, since 2 + 1 + 6 + 7 + 4 + 646 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21674646.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85885 + ... + 86136.

It is an arithmetic number, because the mean of its divisors is an integer number (2236286).

Almost surely, 2^21674646 is an apocalyptic number.

21674646 is an abundant number, since it is smaller than the sum of its proper divisors (31996218).

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

21674646 is a wasteful number, since it uses less digits than its factorization.

21674646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172036 (or 172033 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 21674646 is about 4655.6037202494. The cubic root of 21674646 is about 278.8157723162.

The spelling of 21674646 in words is "twenty-one million, six hundred seventy-four thousand, six hundred forty-six".