21904485 has 16 divisors (see below), whose sum is σ = 35360064. Its totient is φ = 11578112.

The previous prime is 21904471. The next prime is 21904489. The reversal of 21904485 is 58440912.

It is a cyclic number.

It is not a de Polignac number, because 21904485 - 2⁴ = 21904469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21904489) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 4767 + ... + 8156.

It is an arithmetic number, because the mean of its divisors is an integer number (2210004).

Almost surely, 2^21904485 is an apocalyptic number.

It is an amenable number.

21904485 is a deficient number, since it is larger than the sum of its proper divisors (13455579).

21904485 is a wasteful number, since it uses less digits than its factorization.

21904485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13044.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21904485 is about 4680.2227511092. Note that the first 3 decimals coincide. The cubic root of 21904485 is about 279.7978345099.

The spelling of 21904485 in words is "twenty-one million, nine hundred four thousand, four hundred eighty-five".