66706740 has 60 divisors (see below), whose sum is σ = 209266596. Its totient is φ = 17788032.

The previous prime is 66706723. The next prime is 66706753. The reversal of 66706740 is 4760766.

It can be written as a sum of positive squares in 2 ways, for example, as 20412324 + 46294416 = 4518^2 + 6804^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×66706740² = 8899578322855200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 66706695 and 66706704.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18969 + ... + 22208.

Almost surely, 2^66706740 is an apocalyptic number.

66706740 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66706740 is an abundant number, since it is smaller than the sum of its proper divisors (142559856).

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

66706740 is a wasteful number, since it uses less digits than its factorization.

66706740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41198 (or 41187 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 36.

The square root of 66706740 is about 8167.4194210901. The cubic root of 66706740 is about 405.5613614676.

The spelling of 66706740 in words is "sixty-six million, seven hundred six thousand, seven hundred forty".