3507661721 has 2 divisors, whose sum is σ = 3507661722. Its totient is φ = 3507661720.

The previous prime is 3507661693. The next prime is 3507661739. The reversal of 3507661721 is 1271667053.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3136560025 + 371101696 = 56005^2 + 19264^2 .

It is a cyclic number.

It is not a de Polignac number, because 3507661721 - 2⁶ = 3507661657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (3507661321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1753830860 + 1753830861.

It is an arithmetic number, because the mean of its divisors is an integer number (1753830861).

Almost surely, 2^3507661721 is an apocalyptic number.

It is an amenable number.

3507661721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3507661721 is an equidigital number, since it uses as much as digits as its factorization.

3507661721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52920, while the sum is 38.

The square root of 3507661721 is about 59225.5157934484. The cubic root of 3507661721 is about 1519.4015593456.

The spelling of 3507661721 in words is "three billion, five hundred seven million, six hundred sixty-one thousand, seven hundred twenty-one".