2399861 has 4 divisors (see below), whose sum is σ = 2423724. Its totient is φ = 2376000.

The previous prime is 2399821. The next prime is 2399869. The reversal of 2399861 is 1689932.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1918225 + 481636 = 1385^2 + 694^2 .

It is a cyclic number.

It is not a de Polignac number, because 2399861 - 2¹⁴ = 2383477 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 (2399869) 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, 11780 + ... + 11981.

It is an arithmetic number, because the mean of its divisors is an integer number (605931).

2^2399861 is an apocalyptic number.

It is an amenable number.

2399861 is a deficient number, since it is larger than the sum of its proper divisors (23863).

2399861 is a wasteful number, since it uses less digits than its factorization.

2399861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23862.

The product of its digits is 23328, while the sum is 38.

The square root of 2399861 is about 1549.1484757763. The cubic root of 2399861 is about 133.8840052115.

The spelling of 2399861 in words is "two million, three hundred ninety-nine thousand, eight hundred sixty-one".