666698541 has 8 divisors (see below), whose sum is σ = 891408960. Its totient is φ = 443226912.

The previous prime is 666698533. The next prime is 666698573. The reversal of 666698541 is 145896666.

It is a happy number.

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

It is not a de Polignac number, because 666698541 - 2³ = 666698533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666698141) 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, 308440 + ... + 310593.

It is an arithmetic number, because the mean of its divisors is an integer number (111426120).

Almost surely, 2^666698541 is an apocalyptic number.

It is an amenable number.

666698541 is a deficient number, since it is larger than the sum of its proper divisors (224710419).

666698541 is a wasteful number, since it uses less digits than its factorization.

666698541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619395.

The product of its digits is 1866240, while the sum is 51.

The square root of 666698541 is about 25820.5062111493. The cubic root of 666698541 is about 873.5943869119.

The spelling of 666698541 in words is "six hundred sixty-six million, six hundred ninety-eight thousand, five hundred forty-one".