609187561 has 4 divisors (see below), whose sum is σ = 612925072. Its totient is φ = 605450052.

The previous prime is 609187559. The next prime is 609187577. The reversal of 609187561 is 165781906.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165781906 = 2 ⋅82890953.

It is a cyclic number.

It is not a de Polignac number, because 609187561 - 2¹ = 609187559 is a prime.

It is a super-2 number, since 2×609187561² = 742218968954257442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (609187531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1868511 + ... + 1868836.

It is an arithmetic number, because the mean of its divisors is an integer number (153231268).

Almost surely, 2^609187561 is an apocalyptic number.

It is an amenable number.

609187561 is a deficient number, since it is larger than the sum of its proper divisors (3737511).

609187561 is a wasteful number, since it uses less digits than its factorization.

609187561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3737510.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 609187561 is about 24681.7252435886. The cubic root of 609187561 is about 847.7159259890.

The spelling of 609187561 in words is "six hundred nine million, one hundred eighty-seven thousand, five hundred sixty-one".