21540496 has 20 divisors (see below), whose sum is σ = 44190252. Its totient is φ = 10136576.

The previous prime is 21540473. The next prime is 21540529. The reversal of 21540496 is 69404512.

It can be written as a sum of positive squares in 2 ways, for example, as 11806096 + 9734400 = 3436^2 + 3120^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39325 + ... + 39868.

Almost surely, 2^21540496 is an apocalyptic number.

It is an amenable number.

21540496 is an abundant number, since it is smaller than the sum of its proper divisors (22649756).

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

21540496 is a wasteful number, since it uses less digits than its factorization.

21540496 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79218 (or 79212 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 21540496 is about 4641.1739894126. The cubic root of 21540496 is about 278.2393604694.

The spelling of 21540496 in words is "twenty-one million, five hundred forty thousand, four hundred ninety-six".