21854745 has 32 divisors (see below), whose sum is σ = 42387840. Its totient is φ = 10595520.

The previous prime is 21854743. The next prime is 21854771. The reversal of 21854745 is 54745812.

21854745 is a `hidden beast` number, since 2 + 185 + 474 + 5 = 666.

It is not a de Polignac number, because 21854745 - 2¹ = 21854743 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21854743) 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 31 ways as a sum of consecutive naturals, for example, 5874 + ... + 8843.

It is an arithmetic number, because the mean of its divisors is an integer number (1324620).

Almost surely, 2^21854745 is an apocalyptic number.

It is an amenable number.

21854745 is a deficient number, since it is larger than the sum of its proper divisors (20533095).

21854745 is a wasteful number, since it uses less digits than its factorization.

21854745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14742 (or 14736 counting only the distinct ones).

The product of its digits is 44800, while the sum is 36.

The square root of 21854745 is about 4674.9058814055. The cubic root of 21854745 is about 279.5858886945.

The spelling of 21854745 in words is "twenty-one million, eight hundred fifty-four thousand, seven hundred forty-five".