666654651 has 16 divisors (see below), whose sum is σ = 1063609120. Its totient is φ = 410248800.

The previous prime is 666654649. The next prime is 666654679. The reversal of 666654651 is 156456666.

It is not a de Polignac number, because 666654651 - 2¹ = 666654649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666654597 and 666654606.

It is not an unprimeable number, because it can be changed into a prime (666654601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 949300 + ... + 950001.

It is an arithmetic number, because the mean of its divisors is an integer number (66475570).

Almost surely, 2^666654651 is an apocalyptic number.

666654651 is a deficient number, since it is larger than the sum of its proper divisors (396954469).

666654651 is a wasteful number, since it uses less digits than its factorization.

666654651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1899323 (or 1899317 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The square root of 666654651 is about 25819.6562912832. The cubic root of 666654651 is about 873.5752163789.

The spelling of 666654651 in words is "six hundred sixty-six million, six hundred fifty-four thousand, six hundred fifty-one".