20981339 has 8 divisors (see below), whose sum is σ = 22211280. Its totient is φ = 19764000.

The previous prime is 20981293. The next prime is 20981357. The reversal of 20981339 is 93318902.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20981339 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20981299 and 20981308.

It is not an unprimeable number, because it can be changed into a prime (20981369) 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, 389 + ... + 6489.

It is an arithmetic number, because the mean of its divisors is an integer number (2776410).

Almost surely, 2^20981339 is an apocalyptic number.

20981339 is a deficient number, since it is larger than the sum of its proper divisors (1229941).

20981339 is a wasteful number, since it uses less digits than its factorization.

20981339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6301.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 20981339 is about 4580.5391604046. The cubic root of 20981339 is about 275.8106723340.

The spelling of 20981339 in words is "twenty million, nine hundred eighty-one thousand, three hundred thirty-nine".