667406671 has 4 divisors (see below), whose sum is σ = 667458792. Its totient is φ = 667354552.

The previous prime is 667406659. The next prime is 667406681. The reversal of 667406671 is 176604766.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 667406671 - 2⁷ = 667406543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667406681) 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, 7896 + ... + 37378.

It is an arithmetic number, because the mean of its divisors is an integer number (166864698).

Almost surely, 2^667406671 is an apocalyptic number.

667406671 is a deficient number, since it is larger than the sum of its proper divisors (52121).

667406671 is a wasteful number, since it uses less digits than its factorization.

667406671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52120.

The product of its (nonzero) digits is 254016, while the sum is 43.

The square root of 667406671 is about 25834.2151225850. The cubic root of 667406671 is about 873.9035718801.

The spelling of 667406671 in words is "six hundred sixty-seven million, four hundred six thousand, six hundred seventy-one".