21572873 has 8 divisors (see below), whose sum is σ = 25726848. Its totient is φ = 17686944.

The previous prime is 21572867. The next prime is 21572891. The reversal of 21572873 is 37827512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21572873 - 2¹⁴ = 21556489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21574873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66836 + ... + 67157.

It is an arithmetic number, because the mean of its divisors is an integer number (3215856).

Almost surely, 2^21572873 is an apocalyptic number.

21572873 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21572873 is a deficient number, since it is larger than the sum of its proper divisors (4153975).

21572873 is a wasteful number, since it uses less digits than its factorization.

21572873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134023.

The product of its digits is 23520, while the sum is 35.

The square root of 21572873 is about 4644.6606980489. The cubic root of 21572873 is about 278.3786956396.

The spelling of 21572873 in words is "twenty-one million, five hundred seventy-two thousand, eight hundred seventy-three".