665664534 has 24 divisors (see below), whose sum is σ = 1479675960. Its totient is φ = 221824980.

The previous prime is 665664523. The next prime is 665664557. The reversal of 665664534 is 435466566.

665664534 is a `hidden beast` number, since 6 + 6 + 56 + 64 + 534 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 665664534.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 187839 + ... + 191349.

It is an arithmetic number, because the mean of its divisors is an integer number (61653165).

Almost surely, 2^665664534 is an apocalyptic number.

665664534 is an abundant number, since it is smaller than the sum of its proper divisors (814011426).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665664534 is an frugal number, since it uses more digits than its factorization.

665664534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7033 (or 3516 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 45.

The square root of 665664534 is about 25800.4754607352. The cubic root of 665664534 is about 873.1425234650.

The spelling of 665664534 in words is "six hundred sixty-five million, six hundred sixty-four thousand, five hundred thirty-four".