661799401205 has 8 divisors (see below), whose sum is σ = 794270256000. Its totient is φ = 529365537936.

The previous prime is 661799401147. The next prime is 661799401213. The reversal of 661799401205 is 502104997166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661799401205 - 2³⁴ = 644619532021 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9208505 + ... + 9280094.

It is an arithmetic number, because the mean of its divisors is an integer number (99283782000).

Almost surely, 2^661799401205 is an apocalyptic number.

It is an amenable number.

661799401205 is a deficient number, since it is larger than the sum of its proper divisors (132470854795).

661799401205 is a wasteful number, since it uses less digits than its factorization.

661799401205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18495763.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 661799401205 in words is "six hundred sixty-one billion, seven hundred ninety-nine million, four hundred one thousand, two hundred five".