668265019 has 4 divisors (see below), whose sum is σ = 707574744. Its totient is φ = 628955296.

The previous prime is 668265007. The next prime is 668265043. The reversal of 668265019 is 910562866.

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

It is a cyclic number.

It is not a de Polignac number, because 668265019 - 2¹⁵ = 668232251 is a prime.

It is a super-2 number, since 2×668265019² = 893156271238140722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668265049) 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, 19654837 + ... + 19654870.

It is an arithmetic number, because the mean of its divisors is an integer number (176893686).

Almost surely, 2^668265019 is an apocalyptic number.

668265019 is a deficient number, since it is larger than the sum of its proper divisors (39309725).

668265019 is a wasteful number, since it uses less digits than its factorization.

668265019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39309724.

The product of its (nonzero) digits is 155520, while the sum is 43.

The square root of 668265019 is about 25850.8224047128. The cubic root of 668265019 is about 874.2780522248.

The spelling of 668265019 in words is "six hundred sixty-eight million, two hundred sixty-five thousand, nineteen".