3991878472 has 8 divisors (see below), whose sum is σ = 7484772150. Its totient is φ = 1995939232.

The previous prime is 3991878467. The next prime is 3991878479. The reversal of 3991878472 is 2748781993.

It can be written as a sum of positive squares in only one way, i.e., 3905500036 + 86378436 = 62494^2 + 9294^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (3991878479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249492397 + ... + 249492412.

Almost surely, 2^3991878472 is an apocalyptic number.

It is an amenable number.

3991878472 is a deficient number, since it is larger than the sum of its proper divisors (3492893678).

3991878472 is a wasteful number, since it uses less digits than its factorization.

3991878472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498984815 (or 498984811 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 58.

The square root of 3991878472 is about 63181.3142630003. The cubic root of 3991878472 is about 1586.3259805301.

The spelling of 3991878472 in words is "three billion, nine hundred ninety-one million, eight hundred seventy-eight thousand, four hundred seventy-two".