661560599 has 4 divisors (see below), whose sum is σ = 756069264. Its totient is φ = 567051936.

The previous prime is 661560541. The next prime is 661560607. The reversal of 661560599 is 995065166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 995065166 = 2 ⋅497532583.

It is a cyclic number.

It is not a de Polignac number, because 661560599 - 2⁸ = 661560343 is a prime.

It is a super-2 number, since 2×661560599² = 875324852298477602, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661560509) 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, 47254322 + ... + 47254335.

It is an arithmetic number, because the mean of its divisors is an integer number (189017316).

Almost surely, 2^661560599 is an apocalyptic number.

661560599 is a deficient number, since it is larger than the sum of its proper divisors (94508665).

661560599 is an equidigital number, since it uses as much as digits as its factorization.

661560599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94508664.

The product of its (nonzero) digits is 437400, while the sum is 47.

The square root of 661560599 is about 25720.8203407279. The cubic root of 661560599 is about 871.3444659195.

The spelling of 661560599 in words is "six hundred sixty-one million, five hundred sixty thousand, five hundred ninety-nine".