2399991 has 8 divisors (see below), whose sum is σ = 3490944. Its totient is φ = 1454520.

The previous prime is 2399983. The next prime is 2399993. The reversal of 2399991 is 1999932.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2399991 - 2³ = 2399983 is a prime.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2399993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36331 + ... + 36396.

It is an arithmetic number, because the mean of its divisors is an integer number (436368).

2^2399991 is an apocalyptic number.

2399991 is a deficient number, since it is larger than the sum of its proper divisors (1090953).

2399991 is a wasteful number, since it uses less digits than its factorization.

2399991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72741.

The product of its digits is 39366, while the sum is 42.

The square root of 2399991 is about 1549.1904337427. The cubic root of 2399991 is about 133.8864226580.

It can be divided in two parts, 23999 and 91, that added together give a triangular number (24090 = T₂₁₉).

The spelling of 2399991 in words is "two million, three hundred ninety-nine thousand, nine hundred ninety-one".