6445987 has 4 divisors (see below), whose sum is σ = 6493176. Its totient is φ = 6398800.

The previous prime is 6445981. The next prime is 6445991. The reversal of 6445987 is 7895446.

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 6445987 - 2¹⁵ = 6413219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6445981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23389 + ... + 23662.

It is an arithmetic number, because the mean of its divisors is an integer number (1623294).

Almost surely, 2^6445987 is an apocalyptic number.

6445987 is a deficient number, since it is larger than the sum of its proper divisors (47189).

6445987 is a wasteful number, since it uses less digits than its factorization.

6445987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47188.

The product of its digits is 241920, while the sum is 43.

The square root of 6445987 is about 2538.8948383106. The cubic root of 6445987 is about 186.1071856865.

It can be divided in two parts, 64459 and 87, that added together give a palindrome (64546).

The spelling of 6445987 in words is "six million, four hundred forty-five thousand, nine hundred eighty-seven".