667343391 has 16 divisors (see below), whose sum is σ = 1045349760. Its totient is φ = 373338720.

The previous prime is 667343363. The next prime is 667343407. The reversal of 667343391 is 193343766.

It is not a de Polignac number, because 667343391 - 2²⁵ = 633788959 is a prime.

It is a super-2 number, since 2×667343391² = 890694403022757762, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667343311) 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, 777361 + ... + 778218.

It is an arithmetic number, because the mean of its divisors is an integer number (65334360).

Almost surely, 2^667343391 is an apocalyptic number.

667343391 is a deficient number, since it is larger than the sum of its proper divisors (378006369).

667343391 is a wasteful number, since it uses less digits than its factorization.

667343391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1555606.

The product of its digits is 244944, while the sum is 42.

The square root of 667343391 is about 25832.9903611642. The cubic root of 667343391 is about 873.8759513562.

It can be divided in two parts, 66734 and 3391, that added together give a triangular number (70125 = T₃₇₄).

The spelling of 667343391 in words is "six hundred sixty-seven million, three hundred forty-three thousand, three hundred ninety-one".