21450715 has 32 divisors (see below), whose sum is σ = 31852800. Its totient is φ = 13633920.

The previous prime is 21450707. The next prime is 21450727. The reversal of 21450715 is 51705412.

It is not a de Polignac number, because 21450715 - 2³ = 21450707 is a prime.

It is a super-2 number, since 2×21450715² = 920266348022450, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21450715.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12796 + ... + 14374.

It is an arithmetic number, because the mean of its divisors is an integer number (995400).

Almost surely, 2^21450715 is an apocalyptic number.

21450715 is a deficient number, since it is larger than the sum of its proper divisors (10402085).

21450715 is a wasteful number, since it uses less digits than its factorization.

21450715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1627.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 21450715 is about 4631.4916603617. The cubic root of 21450715 is about 277.8522540152.

The spelling of 21450715 in words is "twenty-one million, four hundred fifty thousand, seven hundred fifteen".