21270873 has 16 divisors (see below), whose sum is σ = 30632000. Its totient is φ = 13051584.

The previous prime is 21270871. The next prime is 21270877. The reversal of 21270873 is 37807212.

It is not a de Polignac number, because 21270873 - 2¹ = 21270871 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21270873.

It is not an unprimeable number, because it can be changed into a prime (21270871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18915 + ... + 20007.

It is an arithmetic number, because the mean of its divisors is an integer number (1914500).

Almost surely, 2^21270873 is an apocalyptic number.

It is an amenable number.

21270873 is a deficient number, since it is larger than the sum of its proper divisors (9361127).

21270873 is a wasteful number, since it uses less digits than its factorization.

21270873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1608.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 21270873 is about 4612.0356676851. The cubic root of 21270873 is about 277.0735727971.

The spelling of 21270873 in words is "twenty-one million, two hundred seventy thousand, eight hundred seventy-three".