2539981 has 2 divisors, whose sum is σ = 2539982. Its totient is φ = 2539980.

The previous prime is 2539963. The next prime is 2539997. The reversal of 2539981 is 1899352.

2539981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2528100 + 11881 = 1590^2 + 109^2 .

It is a cyclic number.

It is not a de Polignac number, because 2539981 - 2⁹ = 2539469 is a prime.

It is a super-2 number, since 2×2539981² = 12903006960722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2539981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2539951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1269990 + 1269991.

It is an arithmetic number, because the mean of its divisors is an integer number (1269991).

2^2539981 is an apocalyptic number.

It is an amenable number.

2539981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2539981 is an equidigital number, since it uses as much as digits as its factorization.

2539981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 37.

The square root of 2539981 is about 1593.7317842096. The cubic root of 2539981 is about 136.4405587684.

The spelling of 2539981 in words is "two million, five hundred thirty-nine thousand, nine hundred eighty-one".