3990815172 has 18 divisors (see below), whose sum is σ = 10087893998. Its totient is φ = 1330271712.

The previous prime is 3990815141. The next prime is 3990815177. The reversal of 3990815172 is 2715180993.

It can be written as a sum of positive squares in only one way, i.e., 3251736576 + 739078596 = 57024^2 + 27186^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (3990815177) 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 5 ways as a sum of consecutive naturals, for example, 55427953 + ... + 55428024.

Almost surely, 2^3990815172 is an apocalyptic number.

It is an amenable number.

3990815172 is an abundant number, since it is smaller than the sum of its proper divisors (6097078826).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3990815172 is a wasteful number, since it uses less digits than its factorization.

3990815172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110855987 (or 110855982 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 3990815172 is about 63172.8990311510. The cubic root of 3990815172 is about 1586.1851203467.

The spelling of 3990815172 in words is "three billion, nine hundred ninety million, eight hundred fifteen thousand, one hundred seventy-two".