21804735 has 16 divisors (see below), whose sum is σ = 35367264. Its totient is φ = 11469312.

The previous prime is 21804719. The next prime is 21804737. The reversal of 21804735 is 53740812.

It is not a de Polignac number, because 21804735 - 2⁴ = 21804719 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21804737) 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, 8862 + ... + 11051.

It is an arithmetic number, because the mean of its divisors is an integer number (2210454).

Almost surely, 2^21804735 is an apocalyptic number.

21804735 is a deficient number, since it is larger than the sum of its proper divisors (13562529).

21804735 is a wasteful number, since it uses less digits than its factorization.

21804735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19994.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21804735 is about 4669.5540472298. The cubic root of 21804735 is about 279.3724679339.

The spelling of 21804735 in words is "twenty-one million, eight hundred four thousand, seven hundred thirty-five".