2699239721 has 2 divisors, whose sum is σ = 2699239722. Its totient is φ = 2699239720.

The previous prime is 2699239709. The next prime is 2699239729. The reversal of 2699239721 is 1279329962.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2060161321 + 639078400 = 45389^2 + 25280^2 .

It is a cyclic number.

It is not a de Polignac number, because 2699239721 - 2¹⁰ = 2699238697 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2699239721.

It is not a weakly prime, because it can be changed into another prime (2699239729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1349619860 + 1349619861.

It is an arithmetic number, because the mean of its divisors is an integer number (1349619861).

Almost surely, 2^2699239721 is an apocalyptic number.

It is an amenable number.

2699239721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2699239721 is an equidigital number, since it uses as much as digits as its factorization.

2699239721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 50.

The square root of 2699239721 is about 51954.2079239016. The cubic root of 2699239721 is about 1392.3459377210.

The spelling of 2699239721 in words is "two billion, six hundred ninety-nine million, two hundred thirty-nine thousand, seven hundred twenty-one".