21534705 has 24 divisors (see below), whose sum is σ = 37964160. Its totient is φ = 11289120.

The previous prime is 21534683. The next prime is 21534727. The reversal of 21534705 is 50743512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21534683) and next prime (21534727).

It is not a de Polignac number, because 21534705 - 2⁷ = 21534577 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1401 + ... + 6710.

It is an arithmetic number, because the mean of its divisors is an integer number (1581840).

Almost surely, 2^21534705 is an apocalyptic number.

It is an amenable number.

21534705 is a deficient number, since it is larger than the sum of its proper divisors (16429455).

21534705 is a wasteful number, since it uses less digits than its factorization.

21534705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8181 (or 8178 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21534705 is about 4640.5500751527. The cubic root of 21534705 is about 278.2144240497.

The spelling of 21534705 in words is "twenty-one million, five hundred thirty-four thousand, seven hundred five".