66720586 has 4 divisors (see below), whose sum is σ = 100080882. Its totient is φ = 33360292.

The previous prime is 66720559. The next prime is 66720659. The reversal of 66720586 is 68502766.

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

It can be written as a sum of positive squares in only one way, i.e., 66667225 + 53361 = 8165^2 + 231^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16680145 + ... + 16680148.

Almost surely, 2^66720586 is an apocalyptic number.

66720586 is a deficient number, since it is larger than the sum of its proper divisors (33360296).

66720586 is a wasteful number, since it uses less digits than its factorization.

66720586 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33360295.

The product of its (nonzero) digits is 120960, while the sum is 40.

The square root of 66720586 is about 8168.2670132654. The cubic root of 66720586 is about 405.5894196725.

The spelling of 66720586 in words is "sixty-six million, seven hundred twenty thousand, five hundred eighty-six".