666552121 has 8 divisors (see below), whose sum is σ = 700539840. Its totient is φ = 632981712.

The previous prime is 666552109. The next prime is 666552137. The reversal of 666552121 is 121255666.

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

It is not a de Polignac number, because 666552121 - 2²¹ = 664454969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666552101) 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, 101050 + ... + 107443.

It is an arithmetic number, because the mean of its divisors is an integer number (87567480).

Almost surely, 2^666552121 is an apocalyptic number.

It is an amenable number.

666552121 is a deficient number, since it is larger than the sum of its proper divisors (33987719).

666552121 is a wasteful number, since it uses less digits than its factorization.

666552121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208655.

The product of its digits is 21600, while the sum is 34.

The square root of 666552121 is about 25817.6707121305. The cubic root of 666552121 is about 873.5304294422.

The spelling of 666552121 in words is "six hundred sixty-six million, five hundred fifty-two thousand, one hundred twenty-one".