66561286 has 32 divisors (see below), whose sum is σ = 112764960. Its totient is φ = 29203200.

The previous prime is 66561283. The next prime is 66561289. The reversal of 66561286 is 68216566.

It is an interprime number because it is at equal distance from previous prime (66561283) and next prime (66561289).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66561281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97980 + ... + 98656.

It is an arithmetic number, because the mean of its divisors is an integer number (3523905).

Almost surely, 2^66561286 is an apocalyptic number.

66561286 is a deficient number, since it is larger than the sum of its proper divisors (46203674).

66561286 is a wasteful number, since it uses less digits than its factorization.

66561286 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840.

The product of its digits is 103680, while the sum is 40.

The square root of 66561286 is about 8158.5100355396. The cubic root of 66561286 is about 405.2663715333.

The spelling of 66561286 in words is "sixty-six million, five hundred sixty-one thousand, two hundred eighty-six".