667491647 has 2 divisors, whose sum is σ = 667491648. Its totient is φ = 667491646.

The previous prime is 667491613. The next prime is 667491673. The reversal of 667491647 is 746194766.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 667491647 - 2¹⁰ = 667490623 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 667491595 and 667491604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667491607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333745823 + 333745824.

It is an arithmetic number, because the mean of its divisors is an integer number (333745824).

Almost surely, 2^667491647 is an apocalyptic number.

667491647 is a deficient number, since it is larger than the sum of its proper divisors (1).

667491647 is an equidigital number, since it uses as much as digits as its factorization.

667491647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 50.

The square root of 667491647 is about 25835.8597108747. The cubic root of 667491647 is about 873.9406595518.

The spelling of 667491647 in words is "six hundred sixty-seven million, four hundred ninety-one thousand, six hundred forty-seven".