649987 has 4 divisors (see below), whose sum is σ = 700000. Its totient is φ = 599976.

The previous prime is 649981. The next prime is 649991. The reversal of 649987 is 789946.

649987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-649987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649981) 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, 24987 + ... + 25012.

It is an arithmetic number, because the mean of its divisors is an integer number (175000).

2⁶⁴⁹⁹⁸⁷ is an apocalyptic number.

649987 is a deficient number, since it is larger than the sum of its proper divisors (50013).

649987 is a wasteful number, since it uses less digits than its factorization.

649987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50012.

The product of its digits is 108864, while the sum is 43.

The square root of 649987 is about 806.2177125318. The cubic root of 649987 is about 86.6233330375.

The spelling of 649987 in words is "six hundred forty-nine thousand, nine hundred eighty-seven".