666741257 has 8 divisors (see below), whose sum is σ = 820604736. Its totient is φ = 527531472.

The previous prime is 666741247. The next prime is 666741259. The reversal of 666741257 is 752147666.

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

It is not a de Polignac number, because 666741257 - 2²⁶ = 599632393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666741259) 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, 3663323 + ... + 3663504.

It is an arithmetic number, because the mean of its divisors is an integer number (102575592).

Almost surely, 2^666741257 is an apocalyptic number.

It is an amenable number.

666741257 is a deficient number, since it is larger than the sum of its proper divisors (153863479).

666741257 is a wasteful number, since it uses less digits than its factorization.

666741257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7326847.

The product of its digits is 423360, while the sum is 44.

The square root of 666741257 is about 25821.3333699095. Note that the first 4 decimals coincide. The cubic root of 666741257 is about 873.6130438503.

The spelling of 666741257 in words is "six hundred sixty-six million, seven hundred forty-one thousand, two hundred fifty-seven".