20997339 has 8 divisors (see below), whose sum is σ = 30541632. Its totient is φ = 12725640.

The previous prime is 20997313. The next prime is 20997349. The reversal of 20997339 is 93379902.

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

It is not a de Polignac number, because 20997339 - 2⁷ = 20997211 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20997339.

It is not an unprimeable number, because it can be changed into a prime (20997349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 318109 + ... + 318174.

It is an arithmetic number, because the mean of its divisors is an integer number (3817704).

Almost surely, 2^20997339 is an apocalyptic number.

20997339 is a deficient number, since it is larger than the sum of its proper divisors (9544293).

20997339 is a wasteful number, since it uses less digits than its factorization.

20997339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636297.

The product of its (nonzero) digits is 91854, while the sum is 42.

The square root of 20997339 is about 4582.2853468548. The cubic root of 20997339 is about 275.8807639757.

It can be divided in two parts, 209973 and 39, that added together give a palindrome (210012).

The spelling of 20997339 in words is "twenty million, nine hundred ninety-seven thousand, three hundred thirty-nine".