664666642 has 16 divisors (see below), whose sum is σ = 1012262400. Its totient is φ = 327257280.

The previous prime is 664666577. The next prime is 664666643. The reversal of 664666642 is 246666466.

It is a super-3 number, since 3×664666642³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664666592 and 664666601.

It is not an unprimeable number, because it can be changed into a prime (664666643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140959 + ... + 145597.

It is an arithmetic number, because the mean of its divisors is an integer number (63266400).

Almost surely, 2^664666642 is an apocalyptic number.

664666642 is a deficient number, since it is larger than the sum of its proper divisors (347595758).

664666642 is a wasteful number, since it uses less digits than its factorization.

664666642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5721.

The product of its digits is 1492992, while the sum is 46.

The square root of 664666642 is about 25781.1295718399. The cubic root of 664666642 is about 872.7059984365.

The spelling of 664666642 in words is "six hundred sixty-four million, six hundred sixty-six thousand, six hundred forty-two".