21449540 has 48 divisors (see below), whose sum is σ = 51744000. Its totient is φ = 7316352.

The previous prime is 21449539. The next prime is 21449599. The reversal of 21449540 is 4594412.

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 15 ways as a sum of consecutive naturals, for example, 48641 + ... + 49079.

It is an arithmetic number, because the mean of its divisors is an integer number (1078000).

Almost surely, 2^21449540 is an apocalyptic number.

21449540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21449540 is an abundant number, since it is smaller than the sum of its proper divisors (30294460).

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

21449540 is a wasteful number, since it uses less digits than its factorization.

21449540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804 (or 802 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 21449540 is about 4631.3648096430. The cubic root of 21449540 is about 277.8471806434.

The spelling of 21449540 in words is "twenty-one million, four hundred forty-nine thousand, five hundred forty".