667523643 has 4 divisors (see below), whose sum is σ = 890031528. Its totient is φ = 445015760.

The previous prime is 667523617. The next prime is 667523663. The reversal of 667523643 is 346325766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667523643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 667523595 and 667523604.

It is not an unprimeable number, because it can be changed into a prime (667523603) by changing a digit.

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, 111253938 + ... + 111253943.

It is an arithmetic number, because the mean of its divisors is an integer number (222507882).

Almost surely, 2^667523643 is an apocalyptic number.

667523643 is a deficient number, since it is larger than the sum of its proper divisors (222507885).

667523643 is a wasteful number, since it uses less digits than its factorization.

667523643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222507884.

The product of its digits is 544320, while the sum is 42.

The square root of 667523643 is about 25836.4789203173. The cubic root of 667523643 is about 873.9546233513.

The spelling of 667523643 in words is "six hundred sixty-seven million, five hundred twenty-three thousand, six hundred forty-three".