661802965318 has 16 divisors (see below), whose sum is σ = 1082968192656. Its totient is φ = 300814561440.

The previous prime is 661802965309. The next prime is 661802965319. The reversal of 661802965318 is 813569208166.

It is a super-2 number, since 2×661802965318² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661802965319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1339480 + ... + 1765732.

It is an arithmetic number, because the mean of its divisors is an integer number (67685512041).

Almost surely, 2^661802965318 is an apocalyptic number.

661802965318 is a deficient number, since it is larger than the sum of its proper divisors (421165227338).

661802965318 is a wasteful number, since it uses less digits than its factorization.

661802965318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496839.

The product of its (nonzero) digits is 3732480, while the sum is 55.

The spelling of 661802965318 in words is "six hundred sixty-one billion, eight hundred two million, nine hundred sixty-five thousand, three hundred eighteen".