21375873 has 8 divisors (see below), whose sum is σ = 31668000. Its totient is φ = 14250564.

The previous prime is 21375853. The next prime is 21375889. The reversal of 21375873 is 37857312.

It is not a de Polignac number, because 21375873 - 2⁸ = 21375617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21375853) 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, 395823 + ... + 395876.

It is an arithmetic number, because the mean of its divisors is an integer number (3958500).

Almost surely, 2^21375873 is an apocalyptic number.

It is an amenable number.

21375873 is a deficient number, since it is larger than the sum of its proper divisors (10292127).

21375873 is an equidigital number, since it uses as much as digits as its factorization.

21375873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 791708 (or 791702 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 21375873 is about 4623.4049141298. The cubic root of 21375873 is about 277.5287333286.

The spelling of 21375873 in words is "twenty-one million, three hundred seventy-five thousand, eight hundred seventy-three".