661666115016 has 32 divisors (see below), whose sum is σ = 1837961431200. Its totient is φ = 220555371600.

The previous prime is 661666114981. The next prime is 661666115017. The reversal of 661666115016 is 610511666166.

It is not an unprimeable number, because it can be changed into a prime (661666115017) 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, 1531634310 + ... + 1531634741.

It is an arithmetic number, because the mean of its divisors is an integer number (57436294725).

Almost surely, 2^661666115016 is an apocalyptic number.

It is an amenable number.

661666115016 is an abundant number, since it is smaller than the sum of its proper divisors (1176295316184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661666115016 is a wasteful number, since it uses less digits than its factorization.

661666115016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3063269066 (or 3063269056 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 661666115016 in words is "six hundred sixty-one billion, six hundred sixty-six million, one hundred fifteen thousand, sixteen".