661188311616 has 112 divisors (see below), whose sum is σ = 2053343006336. Its totient is φ = 183805231104.

The previous prime is 661188311611. The next prime is 661188311633. The reversal of 661188311616 is 616113881166.

661188311616 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (661188311611) 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, 6598321 + ... + 6697776.

Almost surely, 2^661188311616 is an apocalyptic number.

It is an amenable number.

661188311616 is an abundant number, since it is smaller than the sum of its proper divisors (1392154694720).

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

661188311616 is a wasteful number, since it uses less digits than its factorization.

661188311616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13296156 (or 13296146 counting only the distinct ones).

The product of its digits is 248832, while the sum is 48.

The spelling of 661188311616 in words is "six hundred sixty-one billion, one hundred eighty-eight million, three hundred eleven thousand, six hundred sixteen".