21649374 has 12 divisors (see below), whose sum is σ = 46907016. Its totient is φ = 7216452.

The previous prime is 21649361. The next prime is 21649429. The reversal of 21649374 is 47394612.

21649374 is a `hidden beast` number, since 2 + 1 + 649 + 3 + 7 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 601354 + ... + 601389.

It is an arithmetic number, because the mean of its divisors is an integer number (3908918).

Almost surely, 2^21649374 is an apocalyptic number.

21649374 is an abundant number, since it is smaller than the sum of its proper divisors (25257642).

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

21649374 is a wasteful number, since it uses less digits than its factorization.

21649374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1202751 (or 1202748 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21649374 is about 4652.8887801021. Note that the first 3 decimals coincide. The cubic root of 21649374 is about 278.7073665082.

The spelling of 21649374 in words is "twenty-one million, six hundred forty-nine thousand, three hundred seventy-four".