66615101 has 4 divisors (see below), whose sum is σ = 76131552. Its totient is φ = 57098652.

The previous prime is 66615079. The next prime is 66615137. The reversal of 66615101 is 10151666.

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 66615101 - 2¹⁰ = 66614077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66615181) 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, 4758215 + ... + 4758228.

It is an arithmetic number, because the mean of its divisors is an integer number (19032888).

Almost surely, 2^66615101 is an apocalyptic number.

It is an amenable number.

66615101 is a deficient number, since it is larger than the sum of its proper divisors (9516451).

66615101 is an equidigital number, since it uses as much as digits as its factorization.

66615101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9516450.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 66615101 is about 8161.8074591355. The cubic root of 66615101 is about 405.3755618053.

Adding to 66615101 its reverse (10151666), we get a palindrome (76766767).

The spelling of 66615101 in words is "sixty-six million, six hundred fifteen thousand, one hundred one".