647666042 has 8 divisors (see below), whose sum is σ = 989829396. Its totient is φ = 317722912.

The previous prime is 647666023. The next prime is 647666057. The reversal of 647666042 is 240666746.

It can be written as a sum of positive squares in 2 ways, for example, as 612513001 + 35153041 = 24749^2 + 5929^2 .

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, 3054923 + ... + 3055134.

Almost surely, 2^647666042 is an apocalyptic number.

647666042 is a deficient number, since it is larger than the sum of its proper divisors (342163354).

647666042 is a wasteful number, since it uses less digits than its factorization.

647666042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6110112.

The product of its (nonzero) digits is 290304, while the sum is 41.

The square root of 647666042 is about 25449.2837227298. The cubic root of 647666042 is about 865.2010589906.

The spelling of 647666042 in words is "six hundred forty-seven million, six hundred sixty-six thousand, forty-two".