21649000 has 32 divisors (see below), whose sum is σ = 50661000. Its totient is φ = 8659200.

The previous prime is 21648997. The next prime is 21649031. The reversal of 21649000 is 94612.

It can be written as a sum of positive squares in 4 ways, for example, as 5116644 + 16532356 = 2262^2 + 4066^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9825 + ... + 11824.

Almost surely, 2^21649000 is an apocalyptic number.

21649000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21649000 is an abundant number, since it is smaller than the sum of its proper divisors (29012000).

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

21649000 is a wasteful number, since it uses less digits than its factorization.

21649000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21670 (or 21656 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 21649000 is about 4652.8485898426. The cubic root of 21649000 is about 278.7057615787.

The spelling of 21649000 in words is "twenty-one million, six hundred forty-nine thousand".