21854315 has 16 divisors (see below), whose sum is σ = 30336768. Its totient is φ = 14803296.

The previous prime is 21854311. The next prime is 21854317. The reversal of 21854315 is 51345812.

It is a cyclic number.

It is not a de Polignac number, because 21854315 - 2² = 21854311 is a prime.

It is a super-2 number, since 2×21854315² = 955222168238450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21854311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 857 + ... + 6666.

It is an arithmetic number, because the mean of its divisors is an integer number (1896048).

Almost surely, 2^21854315 is an apocalyptic number.

21854315 is a deficient number, since it is larger than the sum of its proper divisors (8482453).

21854315 is an equidigital number, since it uses as much as digits as its factorization.

21854315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7618.

The product of its digits is 4800, while the sum is 29.

The square root of 21854315 is about 4674.8598909486. The cubic root of 21854315 is about 279.5840550314.

The spelling of 21854315 in words is "twenty-one million, eight hundred fifty-four thousand, three hundred fifteen".