3971952691 has 10 divisors (see below), whose sum is σ = 4633671892. Its totient is φ = 3404528820.

The previous prime is 3971952643. The next prime is 3971952713. The reversal of 3971952691 is 1962591793.

It is a happy number.

It is not a de Polignac number, because 3971952691 - 2²³ = 3963564083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3971952601) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 824745 + ... + 829546.

Almost surely, 2^3971952691 is an apocalyptic number.

3971952691 is a deficient number, since it is larger than the sum of its proper divisors (661719201).

3971952691 is an frugal number, since it uses more digits than its factorization.

3971952691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1654319 (or 1654298 counting only the distinct ones).

The product of its digits is 918540, while the sum is 52.

The square root of 3971952691 is about 63023.4296988033. The cubic root of 3971952691 is about 1583.6821522983.

The spelling of 3971952691 in words is "three billion, nine hundred seventy-one million, nine hundred fifty-two thousand, six hundred ninety-one".