21372859 has 8 divisors (see below), whose sum is σ = 22690368. Its totient is φ = 20062080.

The previous prime is 21372839. The next prime is 21372887. The reversal of 21372859 is 95827312.

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 21372859 - 2¹⁵ = 21340091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21372839) 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, 5869 + ... + 8785.

It is an arithmetic number, because the mean of its divisors is an integer number (2836296).

Almost surely, 2^21372859 is an apocalyptic number.

21372859 is a deficient number, since it is larger than the sum of its proper divisors (1317509).

21372859 is a wasteful number, since it uses less digits than its factorization.

21372859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3365.

The product of its digits is 30240, while the sum is 37.

The square root of 21372859 is about 4623.0789523866. The cubic root of 21372859 is about 277.5156888568.

The spelling of 21372859 in words is "twenty-one million, three hundred seventy-two thousand, eight hundred fifty-nine".