661110642 has 12 divisors (see below), whose sum is σ = 1432406430. Its totient is φ = 220370208.

The previous prime is 661110623. The next prime is 661110647. The reversal of 661110642 is 246011166.

661110642 is a `hidden beast` number, since 6 + 6 + 1 + 1 + 10 + 642 = 666.

It can be written as a sum of positive squares in only one way, i.e., 659924721 + 1185921 = 25689^2 + 1089^2 .

It is not an unprimeable number, because it can be changed into a prime (661110647) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18364167 + ... + 18364202.

Almost surely, 2^661110642 is an apocalyptic number.

661110642 is an abundant number, since it is smaller than the sum of its proper divisors (771295788).

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

661110642 is a wasteful number, since it uses less digits than its factorization.

661110642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36728377 (or 36728374 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 661110642 is about 25712.0719118472. The cubic root of 661110642 is about 871.1468743139.

The spelling of 661110642 in words is "six hundred sixty-one million, one hundred ten thousand, six hundred forty-two".