3988009 has 3 divisors (see below), whose sum is σ = 3990007.
Its totient is φ = 3986012.
The previous prime is 3988007. The next prime is 3988021. The reversal of 3988009 is 9008893.
The square root of 3988009 is 1997.
It is a perfect power (a square), and thus also a powerful number.
It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9008893 = 23 ⋅391691.
It can be written as a sum of positive squares in only one way, i.e., 99225 + 3888784 = 315^2 + 1972^2
It is not a de Polignac number, because 3988009 - 21 = 3988007 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (3988003) by changing a digit.
It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 999 + ... + 2995.
Almost surely, 23988009 is an apocalyptic number.
3988009 is the 1997-th square number.
3988009 is the 999-th centered octagonal number.
It is an amenable number.
3988009 is a deficient number, since it is larger than the sum of its proper divisors (1998).
3988009 is an frugal number, since it uses more digits than its factorization.
3988009 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3994 (or 1997 counting only the distinct ones).
The product of its (nonzero) digits is 15552, while the sum is 37.
The cubic root of 3988009 is about 158.5813253801.
The spelling of 3988009 in words is "three million, nine hundred eighty-eight thousand, nine".