668071811 has 16 divisors (see below), whose sum is σ = 756898560. Its totient is φ = 584092320.

The previous prime is 668071801. The next prime is 668071843. The reversal of 668071811 is 118170866.

It is a cyclic number.

It is not a de Polignac number, because 668071811 - 2²² = 663877507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668071801) 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, 79916 + ... + 87878.

It is an arithmetic number, because the mean of its divisors is an integer number (47306160).

Almost surely, 2^668071811 is an apocalyptic number.

668071811 is a deficient number, since it is larger than the sum of its proper divisors (88826749).

668071811 is a wasteful number, since it uses less digits than its factorization.

668071811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8266.

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 668071811 is about 25847.0851548100. The cubic root of 668071811 is about 874.1937873544.

The spelling of 668071811 in words is "six hundred sixty-eight million, seventy-one thousand, eight hundred eleven".