667161785 has 4 divisors (see below), whose sum is σ = 800594148. Its totient is φ = 533729424.

The previous prime is 667161773. The next prime is 667161883. The reversal of 667161785 is 587161766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 197009296 + 470152489 = 14036^2 + 21683^2 .

It is a cyclic number.

It is not a de Polignac number, because 667161785 - 2⁴ = 667161769 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66716174 + ... + 66716183.

It is an arithmetic number, because the mean of its divisors is an integer number (200148537).

Almost surely, 2^667161785 is an apocalyptic number.

It is an amenable number.

667161785 is a deficient number, since it is larger than the sum of its proper divisors (133432363).

667161785 is a wasteful number, since it uses less digits than its factorization.

667161785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133432362.

The product of its digits is 423360, while the sum is 47.

The square root of 667161785 is about 25829.4751204898. The cubic root of 667161785 is about 873.7966740724.

The spelling of 667161785 in words is "six hundred sixty-seven million, one hundred sixty-one thousand, seven hundred eighty-five".