666451 has 8 divisors (see below), whose sum is σ = 712800. Its totient is φ = 620928.

The previous prime is 666439. The next prime is 666461. The reversal of 666451 is 154666.

666451 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 666451 - 2¹¹ = 664403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666431) 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, 3250 + ... + 3448.

It is an arithmetic number, because the mean of its divisors is an integer number (89100).

2⁶⁶⁶⁴⁵¹ is an apocalyptic number.

666451 is a deficient number, since it is larger than the sum of its proper divisors (46349).

666451 is a wasteful number, since it uses less digits than its factorization.

666451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413.

The product of its digits is 4320, while the sum is 28.

The square root of 666451 is about 816.3645019230. The cubic root of 666451 is about 87.3486253483.

The spelling of 666451 in words is "six hundred sixty-six thousand, four hundred fifty-one".