665776216 has 32 divisors (see below), whose sum is σ = 1488695040. Its totient is φ = 272926368.

The previous prime is 665776183. The next prime is 665776217. The reversal of 665776216 is 612677566.

It is a Smith number, since the sum of its digits (46) 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 (46).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665776217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257166 + ... + 259741.

It is an arithmetic number, because the mean of its divisors is an integer number (46521720).

Almost surely, 2^665776216 is an apocalyptic number.

It is an amenable number.

665776216 is an abundant number, since it is smaller than the sum of its proper divisors (822918824).

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

665776216 is a wasteful number, since it uses less digits than its factorization.

665776216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516943 (or 516939 counting only the distinct ones).

The product of its digits is 635040, while the sum is 46.

The square root of 665776216 is about 25802.6397099212. The cubic root of 665776216 is about 873.1913512881.

It can be divided in two parts, 665 and 776216, that added together give a triangular number (776881 = T₁₂₄₆).

The spelling of 665776216 in words is "six hundred sixty-five million, seven hundred seventy-six thousand, two hundred sixteen".