668475405 has 24 divisors (see below), whose sum is σ = 1247821848. Its totient is φ = 329095296.

The previous prime is 668475391. The next prime is 668475419. The reversal of 668475405 is 504574866.

668475405 is a `hidden beast` number, since 6 + 68 + 47 + 540 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (668475391) and next prime (668475419).

It can be written as a sum of positive squares in 4 ways, for example, as 15468489 + 653006916 = 3933^2 + 25554^2 .

It is not a de Polignac number, because 668475405 - 2⁴ = 668475389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 570762 + ... + 571931.

It is an arithmetic number, because the mean of its divisors is an integer number (51992577).

Almost surely, 2^668475405 is an apocalyptic number.

668475405 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

668475405 is a deficient number, since it is larger than the sum of its proper divisors (579346443).

668475405 is a wasteful number, since it uses less digits than its factorization.

668475405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142717 (or 1142714 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The square root of 668475405 is about 25854.8913167315. The cubic root of 668475405 is about 874.3697905611.

The spelling of 668475405 in words is "six hundred sixty-eight million, four hundred seventy-five thousand, four hundred five".