609640987 has 4 divisors (see below), whose sum is σ = 630663120. Its totient is φ = 588618856.

The previous prime is 609640979. The next prime is 609640991. The reversal of 609640987 is 789046906.

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 609640987 - 2³ = 609640979 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 609640987.

It is not an unprimeable number, because it can be changed into a prime (609640937) 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, 10511023 + ... + 10511080.

It is an arithmetic number, because the mean of its divisors is an integer number (157665780).

Almost surely, 2^609640987 is an apocalyptic number.

609640987 is a deficient number, since it is larger than the sum of its proper divisors (21022133).

609640987 is a wasteful number, since it uses less digits than its factorization.

609640987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21022132.

The product of its (nonzero) digits is 653184, while the sum is 49.

The square root of 609640987 is about 24690.9089950127. The cubic root of 609640987 is about 847.9261957209.

The spelling of 609640987 in words is "six hundred nine million, six hundred forty thousand, nine hundred eighty-seven".