667642071 has 16 divisors (see below), whose sum is σ = 972960768. Its totient is φ = 405398400.

The previous prime is 667642061. The next prime is 667642093. The reversal of 667642071 is 170246766.

It is not a de Polignac number, because 667642071 - 2¹⁴ = 667625687 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667642021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209565 + ... + 212726.

It is an arithmetic number, because the mean of its divisors is an integer number (60810048).

Almost surely, 2^667642071 is an apocalyptic number.

667642071 is a deficient number, since it is larger than the sum of its proper divisors (305318697).

667642071 is a wasteful number, since it uses less digits than its factorization.

667642071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422342.

The product of its (nonzero) digits is 84672, while the sum is 39.

The square root of 667642071 is about 25838.7706944429. The cubic root of 667642071 is about 874.0063042064.

The spelling of 667642071 in words is "six hundred sixty-seven million, six hundred forty-two thousand, seventy-one".