42399 has 12 divisors (see below), whose sum is σ = 70096. Its totient is φ = 24192.

The previous prime is 42397. The next prime is 42403. The reversal of 42399 is 99324.

42399 = T₄₂ + T₄₃ + ... + T₆₈.

It is not a de Polignac number, because 42399 - 2¹ = 42397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42391) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 274 + ... + 399.

2⁴²³⁹⁹ is an apocalyptic number.

42399 is a deficient number, since it is larger than the sum of its proper divisors (27697).

42399 is a wasteful number, since it uses less digits than its factorization.

42399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686 (or 683 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 42399 is about 205.9101745908. The cubic root of 42399 is about 34.8699938858.

It can be divided in two parts, 42 and 399, that added together give a square (441 = 21²).

The spelling of 42399 in words is "forty-two thousand, three hundred ninety-nine".