664025242 has 4 divisors (see below), whose sum is σ = 996037866. Its totient is φ = 332012620.

The previous prime is 664025227. The next prime is 664025251. The reversal of 664025242 is 242520466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242520466 = 2 ⋅121260233.

It can be written as a sum of positive squares in only one way, i.e., 354230041 + 309795201 = 18821^2 + 17601^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166006309 + ... + 166006312.

Almost surely, 2^664025242 is an apocalyptic number.

664025242 is a deficient number, since it is larger than the sum of its proper divisors (332012624).

664025242 is a wasteful number, since it uses less digits than its factorization.

664025242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332012623.

The product of its (nonzero) digits is 23040, while the sum is 31.

The square root of 664025242 is about 25768.6872385847. The cubic root of 664025242 is about 872.4251891095.

The spelling of 664025242 in words is "six hundred sixty-four million, twenty-five thousand, two hundred forty-two".