667406745779 has 4 divisors (see below), whose sum is σ = 667446586320. Its totient is φ = 667366905240.

The previous prime is 667406745767. The next prime is 667406745787. The reversal of 667406745779 is 977547604766.

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-667406745779 is a prime.

It is a super-2 number, since 2×667406745779² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667406745739) 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, 19895132 + ... + 19928649.

It is an arithmetic number, because the mean of its divisors is an integer number (166861646580).

Almost surely, 2^667406745779 is an apocalyptic number.

667406745779 is a deficient number, since it is larger than the sum of its proper divisors (39840541).

667406745779 is a wasteful number, since it uses less digits than its factorization.

667406745779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39840540.

The product of its (nonzero) digits is 373403520, while the sum is 68.

The spelling of 667406745779 in words is "six hundred sixty-seven billion, four hundred six million, seven hundred forty-five thousand, seven hundred seventy-nine".