21791337 has 8 divisors (see below), whose sum is σ = 29186304. Its totient is φ = 14461968.

The previous prime is 21791333. The next prime is 21791353. The reversal of 21791337 is 73319712.

It is a happy number.

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

It is not a de Polignac number, because 21791337 - 2² = 21791333 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21791298 and 21791307.

It is not an unprimeable number, because it can be changed into a prime (21791333) 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, 15618 + ... + 16955.

It is an arithmetic number, because the mean of its divisors is an integer number (3648288).

Almost surely, 2^21791337 is an apocalyptic number.

It is an amenable number.

21791337 is a deficient number, since it is larger than the sum of its proper divisors (7394967).

21791337 is a wasteful number, since it uses less digits than its factorization.

21791337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32799.

The product of its digits is 7938, while the sum is 33.

The square root of 21791337 is about 4668.1192144160. The cubic root of 21791337 is about 279.3152357284.

The spelling of 21791337 in words is "twenty-one million, seven hundred ninety-one thousand, three hundred thirty-seven".