2563987 has 4 divisors (see below), whose sum is σ = 2574000. Its totient is φ = 2553976.

The previous prime is 2563969. The next prime is 2563997. The reversal of 2563987 is 7893652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2563987 - 2⁷ = 2563859 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2563907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4612 + ... + 5137.

It is an arithmetic number, because the mean of its divisors is an integer number (643500).

2^2563987 is an apocalyptic number.

2563987 is a deficient number, since it is larger than the sum of its proper divisors (10013).

2563987 is an equidigital number, since it uses as much as digits as its factorization.

2563987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10012.

The product of its digits is 90720, while the sum is 40.

The square root of 2563987 is about 1601.2454527648. The cubic root of 2563987 is about 136.8690563365.

The spelling of 2563987 in words is "two million, five hundred sixty-three thousand, nine hundred eighty-seven".