666451015 has 4 divisors (see below), whose sum is σ = 799741224. Its totient is φ = 533160808.

The previous prime is 666451003. The next prime is 666451021. The reversal of 666451015 is 510154666.

It is a happy number.

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 666451015 - 2¹⁹ = 665926727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66645097 + ... + 66645106.

It is an arithmetic number, because the mean of its divisors is an integer number (199935306).

Almost surely, 2^666451015 is an apocalyptic number.

666451015 is a deficient number, since it is larger than the sum of its proper divisors (133290209).

666451015 is a wasteful number, since it uses less digits than its factorization.

666451015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133290208.

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

The square root of 666451015 is about 25815.7125603769. The cubic root of 666451015 is about 873.4862600363.

The spelling of 666451015 in words is "six hundred sixty-six million, four hundred fifty-one thousand, fifteen".