1287623 has 2 divisors, whose sum is σ = 1287624. Its totient is φ = 1287622.

The previous prime is 1287613. The next prime is 1287661. The reversal of 1287623 is 3267821.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1287623 - 2⁴ = 1287607 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1287613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643811 + 643812.

It is an arithmetic number, because the mean of its divisors is an integer number (643812).

2^1287623 is an apocalyptic number.

1287623 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287623 is an equidigital number, since it uses as much as digits as its factorization.

1287623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 1287623 is about 1134.7347707724. The cubic root of 1287623 is about 108.7918199138.

The spelling of 1287623 in words is "one million, two hundred eighty-seven thousand, six hundred twenty-three".