661331052599 has 4 divisors (see below), whose sum is σ = 755806917264. Its totient is φ = 566855187936.

The previous prime is 661331052553. The next prime is 661331052611. The reversal of 661331052599 is 995250133166.

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 661331052599 - 2¹² = 661331048503 is a prime.

It is a super-3 number, since 3×661331052599³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661331052539) 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, 47237932322 + ... + 47237932335.

It is an arithmetic number, because the mean of its divisors is an integer number (188951729316).

Almost surely, 2^661331052599 is an apocalyptic number.

661331052599 is a deficient number, since it is larger than the sum of its proper divisors (94475864665).

661331052599 is an equidigital number, since it uses as much as digits as its factorization.

661331052599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94475864664.

The product of its (nonzero) digits is 1312200, while the sum is 50.

The spelling of 661331052599 in words is "six hundred sixty-one billion, three hundred thirty-one million, fifty-two thousand, five hundred ninety-nine".