3978731642 has 16 divisors (see below), whose sum is σ = 6162504192. Its totient is φ = 1924602960.

The previous prime is 3978731623. The next prime is 3978731671. The reversal of 3978731642 is 2461378793.

3978731642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 248483 + ... + 264009.

It is an arithmetic number, because the mean of its divisors is an integer number (385156512).

Almost surely, 2^3978731642 is an apocalyptic number.

3978731642 is a deficient number, since it is larger than the sum of its proper divisors (2183772550).

3978731642 is a wasteful number, since it uses less digits than its factorization.

3978731642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19693.

The product of its digits is 1524096, while the sum is 50.

The square root of 3978731642 is about 63077.1879683931. The cubic root of 3978731642 is about 1584.5825995737.

The spelling of 3978731642 in words is "three billion, nine hundred seventy-eight million, seven hundred thirty-one thousand, six hundred forty-two".