20990339 has 4 divisors (see below), whose sum is σ = 21068640. Its totient is φ = 20912040.

The previous prime is 20990311. The next prime is 20990353. The reversal of 20990339 is 93309902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20990339 - 2¹² = 20986243 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20990299 and 20990308.

It is not an unprimeable number, because it can be changed into a prime (20990399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38747 + ... + 39284.

It is an arithmetic number, because the mean of its divisors is an integer number (5267160).

Almost surely, 2^20990339 is an apocalyptic number.

20990339 is a deficient number, since it is larger than the sum of its proper divisors (78301).

20990339 is an equidigital number, since it uses as much as digits as its factorization.

20990339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78300.

The product of its (nonzero) digits is 13122, while the sum is 35.

The square root of 20990339 is about 4581.5214721749. The cubic root of 20990339 is about 275.8501032653.

The spelling of 20990339 in words is "twenty million, nine hundred ninety thousand, three hundred thirty-nine".