665151660 has 72 divisors (see below), whose sum is σ = 2037658896. Its totient is φ = 175612800.

The previous prime is 665151647. The next prime is 665151709. The reversal of 665151660 is 66151566.

665151660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 114 + ... + 36473.

It is an arithmetic number, because the mean of its divisors is an integer number (28300818).

Almost surely, 2^665151660 is an apocalyptic number.

665151660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665151660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1018829448).

665151660 is an abundant number, since it is smaller than the sum of its proper divisors (1372507236).

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

665151660 is a wasteful number, since it uses less digits than its factorization.

665151660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36703 (or 36698 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 665151660 is about 25790.5343100914. The cubic root of 665151660 is about 872.9182227182.

It can be divided in two parts, 6651 and 51660, that added together give a triangular number (58311 = T₃₄₁).

The spelling of 665151660 in words is "six hundred sixty-five million, one hundred fifty-one thousand, six hundred sixty".