66561106 has 4 divisors (see below), whose sum is σ = 99841662. Its totient is φ = 33280552.

The previous prime is 66561101. The next prime is 66561127. The reversal of 66561106 is 60116566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60116566 = 2 ⋅30058283.

It can be written as a sum of positive squares in only one way, i.e., 44555625 + 22005481 = 6675^2 + 4691^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (66561101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16640275 + ... + 16640278.

Almost surely, 2^66561106 is an apocalyptic number.

66561106 is a deficient number, since it is larger than the sum of its proper divisors (33280556).

66561106 is a wasteful number, since it uses less digits than its factorization.

66561106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33280555.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 66561106 is about 8158.4990041061. The cubic root of 66561106 is about 405.2660062158.

The spelling of 66561106 in words is "sixty-six million, five hundred sixty-one thousand, one hundred six".