66727840 has 96 divisors (see below), whose sum is σ = 166153680. Its totient is φ = 25288704.

The previous prime is 66727831. The next prime is 66727847. The reversal of 66727840 is 4872766.

It can be written as a sum of positive squares in 8 ways, for example, as 52012944 + 14714896 = 7212^2 + 3836^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 66727793 and 66727802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66727847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 338622 + ... + 338818.

Almost surely, 2^66727840 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 66727840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83076840).

66727840 is an abundant number, since it is smaller than the sum of its proper divisors (99425840).

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

66727840 is a wasteful number, since it uses less digits than its factorization.

66727840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314 (or 306 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 40.

The square root of 66727840 is about 8168.7110366324. The cubic root of 66727840 is about 405.6041179798.

The spelling of 66727840 in words is "sixty-six million, seven hundred twenty-seven thousand, eight hundred forty".