12739721 has 2 divisors, whose sum is σ = 12739722. Its totient is φ = 12739720.

The previous prime is 12739717. The next prime is 12739763. The reversal of 12739721 is 12793721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11485321 + 1254400 = 3389^2 + 1120^2 .

It is a cyclic number.

It is not a de Polignac number, because 12739721 - 2² = 12739717 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12739711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6369860 + 6369861.

It is an arithmetic number, because the mean of its divisors is an integer number (6369861).

Almost surely, 2^12739721 is an apocalyptic number.

It is an amenable number.

12739721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12739721 is an equidigital number, since it uses as much as digits as its factorization.

12739721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5292, while the sum is 32.

The square root of 12739721 is about 3569.2745761569. The cubic root of 12739721 is about 233.5536393208.

It can be divided in two parts, 12739 and 721, that multiplied together give a palindrome (9184819).

The spelling of 12739721 in words is "twelve million, seven hundred thirty-nine thousand, seven hundred twenty-one".