66681101 has 4 divisors (see below), whose sum is σ = 66705600. Its totient is φ = 66656604.

The previous prime is 66681091. The next prime is 66681107. The reversal of 66681101 is 10118666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66681101 - 2⁶ = 66681037 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 (66681107) 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, 7571 + ... + 13808.

It is an arithmetic number, because the mean of its divisors is an integer number (16676400).

Almost surely, 2^66681101 is an apocalyptic number.

It is an amenable number.

66681101 is a deficient number, since it is larger than the sum of its proper divisors (24499).

66681101 is a wasteful number, since it uses less digits than its factorization.

66681101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24498.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 66681101 is about 8165.8496802231. The cubic root of 66681101 is about 405.5093951034.

Adding to 66681101 its reverse (10118666), we get a palindrome (76799767).

The spelling of 66681101 in words is "sixty-six million, six hundred eighty-one thousand, one hundred one".