3947661975 has 48 divisors (see below), whose sum is σ = 6866524800. Its totient is φ = 1998299520.

The previous prime is 3947661973. The next prime is 3947661997. The reversal of 3947661975 is 5791667493.

It is a happy number.

It is not a de Polignac number, because 3947661975 - 2¹ = 3947661973 is a prime.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3947661973) 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 in 47 ways as a sum of consecutive naturals, for example, 112944 + ... + 143706.

It is an arithmetic number, because the mean of its divisors is an integer number (143052600).

Almost surely, 2^3947661975 is an apocalyptic number.

3947661975 is a deficient number, since it is larger than the sum of its proper divisors (2918862825).

3947661975 is a wasteful number, since it uses less digits than its factorization.

3947661975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30864 (or 30859 counting only the distinct ones).

The product of its digits is 8573040, while the sum is 57.

The square root of 3947661975 is about 62830.4223684673. The cubic root of 3947661975 is about 1580.4471808804.

The spelling of 3947661975 in words is "three billion, nine hundred forty-seven million, six hundred sixty-one thousand, nine hundred seventy-five".