3989840978 has 8 divisors (see below), whose sum is σ = 5992272972. Its totient is φ = 1992416656.

The previous prime is 3989840947. The next prime is 3989841001. The reversal of 3989840978 is 8790489893.

It can be written as a sum of positive squares in 2 ways, for example, as 3975680809 + 14160169 = 63053^2 + 3763^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1249925 + ... + 1253112.

Almost surely, 2^3989840978 is an apocalyptic number.

3989840978 is a deficient number, since it is larger than the sum of its proper divisors (2002431994).

3989840978 is a wasteful number, since it uses less digits than its factorization.

3989840978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2503836.

The product of its (nonzero) digits is 31352832, while the sum is 65.

The square root of 3989840978 is about 63165.1880231509. The cubic root of 3989840978 is about 1586.0560424755.

The spelling of 3989840978 in words is "three billion, nine hundred eighty-nine million, eight hundred forty thousand, nine hundred seventy-eight".