21039079739 has 2 divisors, whose sum is σ = 21039079740. Its totient is φ = 21039079738.

The previous prime is 21039079697. The next prime is 21039079741. The reversal of 21039079739 is 93797093012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21039079739 - 2²⁴ = 21022302523 is a prime.

Together with 21039079741, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21039079339) 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, 10519539869 + 10519539870.

It is an arithmetic number, because the mean of its divisors is an integer number (10519539870).

Almost surely, 2^21039079739 is an apocalyptic number.

21039079739 is a deficient number, since it is larger than the sum of its proper divisors (1).

21039079739 is an equidigital number, since it uses as much as digits as its factorization.

21039079739 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 642978, while the sum is 50.

The spelling of 21039079739 in words is "twenty-one billion, thirty-nine million, seventy-nine thousand, seven hundred thirty-nine".