667729161 has 24 divisors (see below), whose sum is σ = 1055941536. Its totient is φ = 403237440.

The previous prime is 667729081. The next prime is 667729163. The reversal of 667729161 is 161927766.

It is a happy number.

It is not a de Polignac number, because 667729161 - 2¹⁰ = 667728137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (667729163) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16101 + ... + 39933.

It is an arithmetic number, because the mean of its divisors is an integer number (43997564).

Almost surely, 2^667729161 is an apocalyptic number.

It is an amenable number.

667729161 is a deficient number, since it is larger than the sum of its proper divisors (388212375).

667729161 is a wasteful number, since it uses less digits than its factorization.

667729161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24133 (or 24130 counting only the distinct ones).

The product of its digits is 190512, while the sum is 45.

The square root of 667729161 is about 25840.4558976811. The cubic root of 667729161 is about 874.0443055561.

The spelling of 667729161 in words is "six hundred sixty-seven million, seven hundred twenty-nine thousand, one hundred sixty-one".