661318655039 has 8 divisors (see below), whose sum is σ = 755806128288. Its totient is φ = 566834526720.

The previous prime is 661318655033. The next prime is 661318655083. The reversal of 661318655039 is 930556813166.

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

It is not a de Polignac number, because 661318655039 - 2⁸ = 661318654783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661318655033) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397202 + ... + 1216719.

It is an arithmetic number, because the mean of its divisors is an integer number (94475766036).

Almost surely, 2^661318655039 is an apocalyptic number.

661318655039 is a deficient number, since it is larger than the sum of its proper divisors (94487473249).

661318655039 is a wasteful number, since it uses less digits than its factorization.

661318655039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1672465.

The product of its (nonzero) digits is 3499200, while the sum is 53.

The spelling of 661318655039 in words is "six hundred sixty-one billion, three hundred eighteen million, six hundred fifty-five thousand, thirty-nine".