666737641 has 4 divisors (see below), whose sum is σ = 676128384. Its totient is φ = 657346900.

The previous prime is 666737623. The next prime is 666737653. The reversal of 666737641 is 146737666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 666737641 - 2⁹ = 666737129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666737591 and 666737600.

It is not an unprimeable number, because it can be changed into a prime (666737741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4695265 + ... + 4695406.

It is an arithmetic number, because the mean of its divisors is an integer number (169032096).

Almost surely, 2^666737641 is an apocalyptic number.

It is an amenable number.

666737641 is a deficient number, since it is larger than the sum of its proper divisors (9390743).

666737641 is an equidigital number, since it uses as much as digits as its factorization.

666737641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9390742.

The product of its digits is 762048, while the sum is 46.

The square root of 666737641 is about 25821.2633501926. The cubic root of 666737641 is about 873.6114645318.

The spelling of 666737641 in words is "six hundred sixty-six million, seven hundred thirty-seven thousand, six hundred forty-one".