3991977 has 16 divisors (see below), whose sum is σ = 6452160. Its totient is φ = 2419200.

The previous prime is 3991973. The next prime is 3991993. The reversal of 3991977 is 7791993.

It is not a de Polignac number, because 3991977 - 2² = 3991973 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3991973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6424 + ... + 7017.

It is an arithmetic number, because the mean of its divisors is an integer number (403260).

Almost surely, 2^3991977 is an apocalyptic number.

It is an amenable number.

3991977 is a deficient number, since it is larger than the sum of its proper divisors (2460183).

3991977 is a wasteful number, since it uses less digits than its factorization.

3991977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13461 (or 13455 counting only the distinct ones).

The product of its digits is 107163, while the sum is 45.

The square root of 3991977 is about 1997.9932432318. The cubic root of 3991977 is about 158.6339031716.

The spelling of 3991977 in words is "three million, nine hundred ninety-one thousand, nine hundred seventy-seven".