668064081 has 4 divisors (see below), whose sum is σ = 890752112. Its totient is φ = 445376052.

The previous prime is 668064041. The next prime is 668064083. The reversal of 668064081 is 180460866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 668064081 - 2¹⁰ = 668063057 is a prime.

It is a super-2 number, since 2×668064081² = 892619232644749122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668064083) 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, 111344011 + ... + 111344016.

It is an arithmetic number, because the mean of its divisors is an integer number (222688028).

Almost surely, 2^668064081 is an apocalyptic number.

It is an amenable number.

668064081 is a deficient number, since it is larger than the sum of its proper divisors (222688031).

668064081 is a wasteful number, since it uses less digits than its factorization.

668064081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222688030.

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 668064081 is about 25846.9356210751. The cubic root of 668064081 is about 874.1904156889.

The spelling of 668064081 in words is "six hundred sixty-eight million, sixty-four thousand, eighty-one".