66746861 has 4 divisors (see below), whose sum is σ = 66785724. Its totient is φ = 66708000.

The previous prime is 66746839. The next prime is 66746881. The reversal of 66746861 is 16864766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34880836 + 31866025 = 5906^2 + 5645^2 .

It is a cyclic number.

It is not a de Polignac number, because 66746861 - 2¹⁰ = 66745837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66746831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16730 + ... + 20331.

It is an arithmetic number, because the mean of its divisors is an integer number (16696431).

Almost surely, 2^66746861 is an apocalyptic number.

It is an amenable number.

66746861 is a deficient number, since it is larger than the sum of its proper divisors (38863).

66746861 is a wasteful number, since it uses less digits than its factorization.

66746861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38862.

The product of its digits is 290304, while the sum is 44.

The square root of 66746861 is about 8169.8752132453. The cubic root of 66746861 is about 405.6426539341.

The spelling of 66746861 in words is "sixty-six million, seven hundred forty-six thousand, eight hundred sixty-one".