3969999 has 16 divisors (see below), whose sum is σ = 6416640. Its totient is φ = 2405880.

The previous prime is 3969997. The next prime is 3970009. The reversal of 3969999 is 9999693.

It is not a de Polignac number, because 3969999 - 2¹ = 3969997 is a prime.

3969999 is a modest number, since divided by 9999 gives 396 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3969997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6387 + ... + 6980.

It is an arithmetic number, because the mean of its divisors is an integer number (401040).

Almost surely, 2^3969999 is an apocalyptic number.

3969999 is a deficient number, since it is larger than the sum of its proper divisors (2446641).

3969999 is a wasteful number, since it uses less digits than its factorization.

3969999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13387 (or 13381 counting only the distinct ones).

The product of its digits is 1062882, while the sum is 54.

The square root of 3969999 is about 1992.4856335743. The cubic root of 3969999 is about 158.3422453586.

The spelling of 3969999 in words is "three million, nine hundred sixty-nine thousand, nine hundred ninety-nine".