66100061 has 4 divisors (see below), whose sum is σ = 66136224. Its totient is φ = 66063900.

The previous prime is 66100051. The next prime is 66100079. The reversal of 66100061 is 16000166.

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 66100061 - 2⁶ = 66099997 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 (66100051) 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, 15185 + ... + 19046.

It is an arithmetic number, because the mean of its divisors is an integer number (16534056).

Almost surely, 2^66100061 is an apocalyptic number.

It is an amenable number.

66100061 is a deficient number, since it is larger than the sum of its proper divisors (36163).

66100061 is a wasteful number, since it uses less digits than its factorization.

66100061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36162.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 66100061 is about 8130.1944011198. The cubic root of 66100061 is about 404.3281264751.

The spelling of 66100061 in words is "sixty-six million, one hundred thousand, sixty-one".