21854573 has 12 divisors (see below), whose sum is σ = 23947380. Its totient is φ = 19933056.

The previous prime is 21854563. The next prime is 21854587. The reversal of 21854573 is 37545812.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1261129 + 20593444 = 1123^2 + 4538^2 .

It is not a de Polignac number, because 21854573 - 2⁸ = 21854317 is a prime.

It is a super-2 number, since 2×21854573² = 955244722024658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854533) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14315 + ... + 15767.

It is an arithmetic number, because the mean of its divisors is an integer number (1995615).

Almost surely, 2^21854573 is an apocalyptic number.

It is an amenable number.

21854573 is a deficient number, since it is larger than the sum of its proper divisors (2092807).

21854573 is a wasteful number, since it uses less digits than its factorization.

21854573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1568 (or 1555 counting only the distinct ones).

The product of its digits is 33600, while the sum is 35.

The square root of 21854573 is about 4674.8874852771. The cubic root of 21854573 is about 279.5851552321.

The spelling of 21854573 in words is "twenty-one million, eight hundred fifty-four thousand, five hundred seventy-three".