666122261 has 8 divisors (see below), whose sum is σ = 761442624. Its totient is φ = 570841920.

The previous prime is 666122221. The next prime is 666122263. The reversal of 666122261 is 162221666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666122261 - 2¹⁴ = 666105877 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666122263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48446 + ... + 60656.

It is an arithmetic number, because the mean of its divisors is an integer number (95180328).

Almost surely, 2^666122261 is an apocalyptic number.

It is an amenable number.

666122261 is a deficient number, since it is larger than the sum of its proper divisors (95320363).

666122261 is a wasteful number, since it uses less digits than its factorization.

666122261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20011.

The product of its digits is 10368, while the sum is 32.

The square root of 666122261 is about 25809.3444511867. The cubic root of 666122261 is about 873.3426089019.

The spelling of 666122261 in words is "six hundred sixty-six million, one hundred twenty-two thousand, two hundred sixty-one".