661342666 has 8 divisors (see below), whose sum is σ = 1015084224. Its totient is φ = 322981260.

The previous prime is 661342637. The next prime is 661342673. The reversal of 661342666 is 666243166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3844930 + ... + 3845101.

It is an arithmetic number, because the mean of its divisors is an integer number (126885528).

Almost surely, 2^661342666 is an apocalyptic number.

661342666 is a deficient number, since it is larger than the sum of its proper divisors (353741558).

661342666 is a wasteful number, since it uses less digits than its factorization.

661342666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7690076.

The product of its digits is 186624, while the sum is 40.

The square root of 661342666 is about 25716.5834822591. The cubic root of 661342666 is about 871.2487752302.

The spelling of 661342666 in words is "six hundred sixty-one million, three hundred forty-two thousand, six hundred sixty-six".