3956982661 has 4 divisors (see below), whose sum is σ = 3957141024. Its totient is φ = 3956824300.

The previous prime is 3956982647. The next prime is 3956982697. The reversal of 3956982661 is 1662896593.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1662896593 = 1373 ⋅1211141.

It is a cyclic number.

It is not a de Polignac number, because 3956982661 - 2⁹ = 3956982149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3956982061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32545 + ... + 94726.

It is an arithmetic number, because the mean of its divisors is an integer number (989285256).

Almost surely, 2^3956982661 is an apocalyptic number.

It is an amenable number.

3956982661 is a deficient number, since it is larger than the sum of its proper divisors (158363).

3956982661 is a wasteful number, since it uses less digits than its factorization.

3956982661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158362.

The product of its digits is 4199040, while the sum is 55.

The square root of 3956982661 is about 62904.5519895023. The cubic root of 3956982661 is about 1581.6900493335.

The spelling of 3956982661 in words is "three billion, nine hundred fifty-six million, nine hundred eighty-two thousand, six hundred sixty-one".