21495216 has 20 divisors (see below), whose sum is σ = 55529432. Its totient is φ = 7165056.

The previous prime is 21495197. The next prime is 21495217. The reversal of 21495216 is 61259412.

It is not an unprimeable number, because it can be changed into a prime (21495217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223861 + ... + 223956.

Almost surely, 2^21495216 is an apocalyptic number.

It is an amenable number.

21495216 is an abundant number, since it is smaller than the sum of its proper divisors (34034216).

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

21495216 is a wasteful number, since it uses less digits than its factorization.

21495216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447828 (or 447822 counting only the distinct ones).

The product of its digits is 4320, while the sum is 30.

The square root of 21495216 is about 4636.2933470608. The cubic root of 21495216 is about 278.0442625725.

The spelling of 21495216 in words is "twenty-one million, four hundred ninety-five thousand, two hundred sixteen".