3988691 has 4 divisors (see below), whose sum is σ = 4558512. Its totient is φ = 3418872.

The previous prime is 3988687. The next prime is 3988703. The reversal of 3988691 is 1968893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1968893 = 709 ⋅2777.

It is a cyclic number.

It is not a de Polignac number, because 3988691 - 2² = 3988687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3988601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 284900 + ... + 284913.

It is an arithmetic number, because the mean of its divisors is an integer number (1139628).

Almost surely, 2^3988691 is an apocalyptic number.

3988691 is a deficient number, since it is larger than the sum of its proper divisors (569821).

3988691 is an equidigital number, since it uses as much as digits as its factorization.

3988691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569820.

The product of its digits is 93312, while the sum is 44.

The square root of 3988691 is about 1997.1707488345. The cubic root of 3988691 is about 158.5903646693.

The spelling of 3988691 in words is "three million, nine hundred eighty-eight thousand, six hundred ninety-one".