661166166120 has 64 divisors (see below), whose sum is σ = 1988494859520. Its totient is φ = 175866856704.

The previous prime is 661166166061. The next prime is 661166166121. The reversal of 661166166120 is 21661661166.

It is not an unprimeable number, because it can be changed into a prime (661166166121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6891552 + ... + 6986831.

It is an arithmetic number, because the mean of its divisors is an integer number (31070232180).

Almost surely, 2^661166166120 is an apocalyptic number.

661166166120 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

661166166120 is an abundant number, since it is smaller than the sum of its proper divisors (1327328693400).

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

661166166120 is a wasteful number, since it uses less digits than its factorization.

661166166120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13878794 (or 13878790 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The spelling of 661166166120 in words is "six hundred sixty-one billion, one hundred sixty-six million, one hundred sixty-six thousand, one hundred twenty".