66181960 has 64 divisors (see below), whose sum is σ = 161708400. Its totient is φ = 24231936.

The previous prime is 66181957. The next prime is 66181981. The reversal of 66181960 is 6918166.

It can be written as a sum of positive squares in 8 ways, for example, as 3740356 + 62441604 = 1934^2 + 7902^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70776 + ... + 71704.

Almost surely, 2^66181960 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 66181960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80854200).

66181960 is an abundant number, since it is smaller than the sum of its proper divisors (95526440).

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

66181960 is a wasteful number, since it uses less digits than its factorization.

66181960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090 (or 1086 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 66181960 is about 8135.2295603750. The cubic root of 66181960 is about 404.4950471600.

It can be divided in two parts, 661 and 81960, that added together give a triangular number (82621 = T₄₀₆).

The spelling of 66181960 in words is "sixty-six million, one hundred eighty-one thousand, nine hundred sixty".