66725569 has 4 divisors (see below), whose sum is σ = 67984596. Its totient is φ = 65466544.

The previous prime is 66725567. The next prime is 66725579. The reversal of 66725569 is 96552766.

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 26884225 + 39841344 = 5185^2 + 6312^2 .

It is a cyclic number.

It is not a de Polignac number, because 66725569 - 2¹ = 66725567 is a prime.

It is a super-2 number, since 2×66725569² = 8904603116747522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66725567) 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, 629434 + ... + 629539.

It is an arithmetic number, because the mean of its divisors is an integer number (16996149).

Almost surely, 2^66725569 is an apocalyptic number.

It is an amenable number.

66725569 is a deficient number, since it is larger than the sum of its proper divisors (1259027).

66725569 is a wasteful number, since it uses less digits than its factorization.

66725569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1259026.

The product of its digits is 680400, while the sum is 46.

The square root of 66725569 is about 8168.5720294308. The cubic root of 66725569 is about 405.5995165151.

The spelling of 66725569 in words is "sixty-six million, seven hundred twenty-five thousand, five hundred sixty-nine".