20949239 has 2 divisors, whose sum is σ = 20949240. Its totient is φ = 20949238.

The previous prime is 20949221. The next prime is 20949241. The reversal of 20949239 is 93294902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20949239 - 2²⁰ = 19900663 is a prime.

It is a super-2 number, since 2×20949239² = 877741229358242, which contains 22 as substring.

Together with 20949241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20949259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10474619 + 10474620.

It is an arithmetic number, because the mean of its divisors is an integer number (10474620).

Almost surely, 2^20949239 is an apocalyptic number.

20949239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20949239 is an equidigital number, since it uses as much as digits as its factorization.

20949239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 20949239 is about 4577.0338648518. The cubic root of 20949239 is about 275.6699434461.

The spelling of 20949239 in words is "twenty million, nine hundred forty-nine thousand, two hundred thirty-nine".