666612061 has 4 divisors (see below), whose sum is σ = 666972124. Its totient is φ = 666252000.

The previous prime is 666612029. The next prime is 666612097. The reversal of 666612061 is 160216666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 109935225 + 556676836 = 10485^2 + 23594^2 .

It is a cyclic number.

It is not a de Polignac number, because 666612061 - 2⁵ = 666612029 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 (666612361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177240 + ... + 180961.

It is an arithmetic number, because the mean of its divisors is an integer number (166743031).

Almost surely, 2^666612061 is an apocalyptic number.

It is an amenable number.

666612061 is a deficient number, since it is larger than the sum of its proper divisors (360063).

666612061 is a wasteful number, since it uses less digits than its factorization.

666612061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360062.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 666612061 is about 25818.8315188740. The cubic root of 666612061 is about 873.5566128632.

The spelling of 666612061 in words is "six hundred sixty-six million, six hundred twelve thousand, sixty-one".