665133612 has 144 divisors (see below), whose sum is σ = 1856875776. Its totient is φ = 184060800.

The previous prime is 665133593. The next prime is 665133631. The reversal of 665133612 is 216331566.

It is an interprime number because it is at equal distance from previous prime (665133593) and next prime (665133631).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3152187 + ... + 3152397.

Almost surely, 2^665133612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665133612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928437888).

665133612 is an abundant number, since it is smaller than the sum of its proper divisors (1191742164).

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

665133612 is a wasteful number, since it uses less digits than its factorization.

665133612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420 (or 407 counting only the distinct ones).

The product of its digits is 19440, while the sum is 33.

The square root of 665133612 is about 25790.1844119037. The cubic root of 665133612 is about 872.9103274909.

It can be divided in two parts, 66513 and 3612, that added together give a triangular number (70125 = T₃₇₄).

The spelling of 665133612 in words is "six hundred sixty-five million, one hundred thirty-three thousand, six hundred twelve".