2539661 has 2 divisors, whose sum is σ = 2539662. Its totient is φ = 2539660.

The previous prime is 2539657. The next prime is 2539699. The reversal of 2539661 is 1669352.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1394761 + 1144900 = 1181^2 + 1070^2 .

It is a cyclic number.

It is not a de Polignac number, because 2539661 - 2² = 2539657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2539631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1269830 + 1269831.

It is an arithmetic number, because the mean of its divisors is an integer number (1269831).

2^2539661 is an apocalyptic number.

It is an amenable number.

2539661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2539661 is an equidigital number, since it uses as much as digits as its factorization.

2539661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 32.

The square root of 2539661 is about 1593.6313877431. The cubic root of 2539661 is about 136.4348286977.

The spelling of 2539661 in words is "two million, five hundred thirty-nine thousand, six hundred sixty-one".