3969240721 has 2 divisors, whose sum is σ = 3969240722. Its totient is φ = 3969240720.

The previous prime is 3969240697. The next prime is 3969240727. The reversal of 3969240721 is 1270429693.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3517083025 + 452157696 = 59305^2 + 21264^2 .

It is a cyclic number.

It is not a de Polignac number, because 3969240721 - 2²⁷ = 3835022993 is a prime.

It is not a weakly prime, because it can be changed into another prime (3969240727) 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, 1984620360 + 1984620361.

It is an arithmetic number, because the mean of its divisors is an integer number (1984620361).

Almost surely, 2^3969240721 is an apocalyptic number.

It is an amenable number.

3969240721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3969240721 is an equidigital number, since it uses as much as digits as its factorization.

3969240721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 3969240721 is about 63001.9104551600. The cubic root of 3969240721 is about 1583.3216347157.

The spelling of 3969240721 in words is "three billion, nine hundred sixty-nine million, two hundred forty thousand, seven hundred twenty-one".