665156814 has 16 divisors (see below), whose sum is σ = 1520358528. Its totient is φ = 190044792.

The previous prime is 665156813. The next prime is 665156819. The reversal of 665156814 is 418651566.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 15837067 = 665156814 / (6 + 6 + 5 + 1 + 5 + 6 + 8 + 1 + 4).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665156813) 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, 7918492 + ... + 7918575.

It is an arithmetic number, because the mean of its divisors is an integer number (95022408).

Almost surely, 2^665156814 is an apocalyptic number.

665156814 is an abundant number, since it is smaller than the sum of its proper divisors (855201714).

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

665156814 is a wasteful number, since it uses less digits than its factorization.

665156814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15837079.

The product of its digits is 172800, while the sum is 42.

The square root of 665156814 is about 25790.6342302782. The cubic root of 665156814 is about 872.9204773463.

It can be divided in two parts, 6 and 65156814, that added together give a triangular number (65156820 = T₁₁₄₁₅).

The spelling of 665156814 in words is "six hundred sixty-five million, one hundred fifty-six thousand, eight hundred fourteen".