6431987 has 2 divisors, whose sum is σ = 6431988. Its totient is φ = 6431986.

The previous prime is 6431977. The next prime is 6431993. The reversal of 6431987 is 7891346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6431987 - 2¹² = 6427891 is a prime.

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 6431987.

It is not a weakly prime, because it can be changed into another prime (6431977) 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, 3215993 + 3215994.

It is an arithmetic number, because the mean of its divisors is an integer number (3215994).

Almost surely, 2^6431987 is an apocalyptic number.

6431987 is a deficient number, since it is larger than the sum of its proper divisors (1).

6431987 is an equidigital number, since it uses as much as digits as its factorization.

6431987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 38.

The square root of 6431987 is about 2536.1362345111. The cubic root of 6431987 is about 185.9723530033.

The spelling of 6431987 in words is "six million, four hundred thirty-one thousand, nine hundred eighty-seven".