668161571 has 16 divisors (see below), whose sum is σ = 835211520. Its totient is φ = 519283680.

The previous prime is 668161517. The next prime is 668161573. The reversal of 668161571 is 175161866.

It is a cyclic number.

It is not a de Polignac number, because 668161571 - 2¹⁰ = 668160547 is a prime.

It is a super-2 number, since 2×668161571² = 892879769922376082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (668161573) 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, 18800 + ... + 41106.

It is an arithmetic number, because the mean of its divisors is an integer number (52200720).

Almost surely, 2^668161571 is an apocalyptic number.

668161571 is a deficient number, since it is larger than the sum of its proper divisors (167049949).

668161571 is a wasteful number, since it uses less digits than its factorization.

668161571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22714.

The product of its digits is 60480, while the sum is 41.

The square root of 668161571 is about 25848.8214624961. The cubic root of 668161571 is about 874.2329368984.

The spelling of 668161571 in words is "six hundred sixty-eight million, one hundred sixty-one thousand, five hundred seventy-one".