66760909 has 4 divisors (see below), whose sum is σ = 67675516. Its totient is φ = 65846304.

The previous prime is 66760891. The next prime is 66760933. The reversal of 66760909 is 90906766.

It is a happy number.

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 23068809 + 43692100 = 4803^2 + 6610^2 .

It is a cyclic number.

It is not a de Polignac number, because 66760909 - 2¹⁷ = 66629837 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 (66760999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 457194 + ... + 457339.

It is an arithmetic number, because the mean of its divisors is an integer number (16918879).

Almost surely, 2^66760909 is an apocalyptic number.

It is an amenable number.

66760909 is a deficient number, since it is larger than the sum of its proper divisors (914607).

66760909 is an equidigital number, since it uses as much as digits as its factorization.

66760909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914606.

The product of its (nonzero) digits is 122472, while the sum is 43.

The square root of 66760909 is about 8170.7349118669. The cubic root of 66760909 is about 405.6711100452.

The spelling of 66760909 in words is "sixty-six million, seven hundred sixty thousand, nine hundred nine".