21483540 has 72 divisors (see below), whose sum is σ = 70187208. Its totient is φ = 5287680.

The previous prime is 21483533. The next prime is 21483557. The reversal of 21483540 is 4538412.

It can be written as a sum of positive squares in 4 ways, for example, as 853776 + 20629764 = 924^2 + 4542^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2251 + ... + 6930.

Almost surely, 2^21483540 is an apocalyptic number.

21483540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21483540 is an abundant number, since it is smaller than the sum of its proper divisors (48703668).

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

21483540 is a wasteful number, since it uses less digits than its factorization.

21483540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9209 (or 9204 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 21483540 is about 4635.0339804580. The cubic root of 21483540 is about 277.9939097746.

The spelling of 21483540 in words is "twenty-one million, four hundred eighty-three thousand, five hundred forty".