21840735 has 32 divisors (see below), whose sum is σ = 40458240. Its totient is φ = 9854208.

The previous prime is 21840691. The next prime is 21840743. The reversal of 21840735 is 53704812.

It is not a de Polignac number, because 21840735 - 2⁷ = 21840607 is a prime.

It is a congruent number.

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, 6979 + ... + 9611.

It is an arithmetic number, because the mean of its divisors is an integer number (1264320).

Almost surely, 2^21840735 is an apocalyptic number.

21840735 is a deficient number, since it is larger than the sum of its proper divisors (18617505).

21840735 is a wasteful number, since it uses less digits than its factorization.

21840735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2727.

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

The square root of 21840735 is about 4673.4072152981. The cubic root of 21840735 is about 279.5261330122.

The spelling of 21840735 in words is "twenty-one million, eight hundred forty thousand, seven hundred thirty-five".