664742 has 16 divisors (see below), whose sum is σ = 1104432. Its totient is φ = 298080.

The previous prime is 664739. The next prime is 664757. The reversal of 664742 is 247466.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664742.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 617 + ... + 1307.

It is an arithmetic number, because the mean of its divisors is an integer number (69027).

2⁶⁶⁴⁷⁴² is an apocalyptic number.

664742 is a deficient number, since it is larger than the sum of its proper divisors (439690).

664742 is a wasteful number, since it uses less digits than its factorization.

664742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743.

The product of its digits is 8064, while the sum is 29.

The square root of 664742 is about 815.3171162192. The cubic root of 664742 is about 87.2738978826.

The spelling of 664742 in words is "six hundred sixty-four thousand, seven hundred forty-two".