3999920 has 20 divisors (see below), whose sum is σ = 9300000. Its totient is φ = 1599936.

The previous prime is 3999917. The next prime is 3999923. The reversal of 3999920 is 299993.

It is an interprime number because it is at equal distance from previous prime (3999917) and next prime (3999923).

It is a tau number, because it is divible by the number of its divisors (20).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (3999923) 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, 24920 + ... + 25079.

It is an arithmetic number, because the mean of its divisors is an integer number (465000).

Almost surely, 2^3999920 is an apocalyptic number.

It is an amenable number.

3999920 is an abundant number, since it is smaller than the sum of its proper divisors (5300080).

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

3999920 is a wasteful number, since it uses less digits than its factorization.

3999920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50012 (or 50006 counting only the distinct ones).

The product of its (nonzero) digits is 39366, while the sum is 41.

The square root of 3999920 is about 1999.9799999000. The cubic root of 3999920 is about 158.7390469224.

The spelling of 3999920 in words is "three million, nine hundred ninety-nine thousand, nine hundred twenty".