667895521 has 4 divisors (see below), whose sum is σ = 682106112. Its totient is φ = 653684932.

The previous prime is 667895513. The next prime is 667895531. The reversal of 667895521 is 125598766.

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, and also an emirpimes, since its reverse is a distinct semiprime: 125598766 = 2 ⋅62799383.

It is a cyclic number.

It is not a de Polignac number, because 667895521 - 2³ = 667895513 is a prime.

It is a super-2 number, since 2×667895521² = 892168853943722882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (667895531) 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, 7105225 + ... + 7105318.

It is an arithmetic number, because the mean of its divisors is an integer number (170526528).

Almost surely, 2^667895521 is an apocalyptic number.

It is an amenable number.

667895521 is a deficient number, since it is larger than the sum of its proper divisors (14210591).

667895521 is a wasteful number, since it uses less digits than its factorization.

667895521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14210590.

The product of its digits is 907200, while the sum is 49.

The square root of 667895521 is about 25843.6746806641. The cubic root of 667895521 is about 874.1168868487.

The spelling of 667895521 in words is "six hundred sixty-seven million, eight hundred ninety-five thousand, five hundred twenty-one".