1287431 has 2 divisors, whose sum is σ = 1287432. Its totient is φ = 1287430.

The previous prime is 1287401. The next prime is 1287457. The reversal of 1287431 is 1347821.

It is an a-pointer prime, because the next prime (1287457) can be obtained adding 1287431 to its sum of digits (26).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1287431 - 2¹⁴ = 1271047 is a prime.

It is a super-2 number, since 2×1287431² = 3314957159522, 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 1287431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1287401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643715 + 643716.

It is an arithmetic number, because the mean of its divisors is an integer number (643716).

2^1287431 is an apocalyptic number.

1287431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287431 is an equidigital number, since it uses as much as digits as its factorization.

1287431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 26.

The square root of 1287431 is about 1134.6501663508. The cubic root of 1287431 is about 108.7864122575.

The spelling of 1287431 in words is "one million, two hundred eighty-seven thousand, four hundred thirty-one".