2239981 has 4 divisors (see below), whose sum is σ = 2276764. Its totient is φ = 2203200.

The previous prime is 2239961. The next prime is 2239987. The reversal of 2239981 is 1899322.

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 19881 + 2220100 = 141^2 + 1490^2 .

It is a cyclic number.

It is not a de Polignac number, because 2239981 - 2⁵ = 2239949 is a prime.

It is a super-2 number, since 2×2239981² = 10035029760722, which contains 22 as substring.

It is an Ulam number.

2239981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2239987) 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, 18300 + ... + 18421.

It is an arithmetic number, because the mean of its divisors is an integer number (569191).

2^2239981 is an apocalyptic number.

It is an amenable number.

2239981 is a deficient number, since it is larger than the sum of its proper divisors (36783).

2239981 is an equidigital number, since it uses as much as digits as its factorization.

2239981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36782.

The product of its digits is 7776, while the sum is 34.

The square root of 2239981 is about 1496.6566072416. The cubic root of 2239981 is about 130.8422824645.

The spelling of 2239981 in words is "two million, two hundred thirty-nine thousand, nine hundred eighty-one".