21649338 has 12 divisors (see below), whose sum is σ = 46906938. Its totient is φ = 7216440.

The previous prime is 21649319. The next prime is 21649349. The reversal of 21649338 is 83394612.

21649338 is a `hidden beast` number, since 2 + 1 + 649 + 3 + 3 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13198689 + 8450649 = 3633^2 + 2907^2 .

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, 601353 + ... + 601388.

Almost surely, 2^21649338 is an apocalyptic number.

21649338 is an abundant number, since it is smaller than the sum of its proper divisors (25257600).

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

21649338 is a wasteful number, since it uses less digits than its factorization.

21649338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1202749 (or 1202746 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 21649338 is about 4652.8849115361. The cubic root of 21649338 is about 278.7072120238.

The spelling of 21649338 in words is "twenty-one million, six hundred forty-nine thousand, three hundred thirty-eight".