1239661 has 2 divisors, whose sum is σ = 1239662. Its totient is φ = 1239660.

The previous prime is 1239643. The next prime is 1239671. The reversal of 1239661 is 1669321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 792100 + 447561 = 890^2 + 669^2 .

It is a cyclic number.

It is not a de Polignac number, because 1239661 - 2⁷ = 1239533 is a prime.

1239661 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1239671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 619830 + 619831.

It is an arithmetic number, because the mean of its divisors is an integer number (619831).

2^1239661 is an apocalyptic number.

It is an amenable number.

1239661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1239661 is an equidigital number, since it uses as much as digits as its factorization.

1239661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 28.

The square root of 1239661 is about 1113.4006466677. The cubic root of 1239661 is about 107.4239158768.

The spelling of 1239661 in words is "one million, two hundred thirty-nine thousand, six hundred sixty-one".