666946051 has 4 divisors (see below), whose sum is σ = 669713704. Its totient is φ = 664178400.

The previous prime is 666946009. The next prime is 666946069. The reversal of 666946051 is 150649666.

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

It is a cyclic number.

It is not a de Polignac number, because 666946051 - 2¹⁵ = 666913283 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666945989 and 666946007.

It is not an unprimeable number, because it can be changed into a prime (666946081) 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, 1383465 + ... + 1383946.

It is an arithmetic number, because the mean of its divisors is an integer number (167428426).

Almost surely, 2^666946051 is an apocalyptic number.

666946051 is a deficient number, since it is larger than the sum of its proper divisors (2767653).

666946051 is a wasteful number, since it uses less digits than its factorization.

666946051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2767652.

The product of its (nonzero) digits is 233280, while the sum is 43.

The square root of 666946051 is about 25825.2986623582. The cubic root of 666946051 is about 873.7024800412.

The spelling of 666946051 in words is "six hundred sixty-six million, nine hundred forty-six thousand, fifty-one".