665542984 has 8 divisors (see below), whose sum is σ = 1247893110. Its totient is φ = 332771488.

The previous prime is 665542967. The next prime is 665542987. The reversal of 665542984 is 489245566.

It can be written as a sum of positive squares in only one way, i.e., 555922084 + 109620900 = 23578^2 + 10470^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (665542987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41596429 + ... + 41596444.

Almost surely, 2^665542984 is an apocalyptic number.

It is an amenable number.

665542984 is a deficient number, since it is larger than the sum of its proper divisors (582350126).

665542984 is a wasteful number, since it uses less digits than its factorization.

665542984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83192879 (or 83192875 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 49.

The square root of 665542984 is about 25798.1197764488. The cubic root of 665542984 is about 873.0893751053.

The spelling of 665542984 in words is "six hundred sixty-five million, five hundred forty-two thousand, nine hundred eighty-four".