666574399 has 2 divisors, whose sum is σ = 666574400. Its totient is φ = 666574398.

The previous prime is 666574379. The next prime is 666574409. The reversal of 666574399 is 993475666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666574399 - 2¹³ = 666566207 is a prime.

It is a super-2 number, since 2×666574399² = 888642858804422402, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666574379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333287199 + 333287200.

It is an arithmetic number, because the mean of its divisors is an integer number (333287200).

Almost surely, 2^666574399 is an apocalyptic number.

666574399 is a deficient number, since it is larger than the sum of its proper divisors (1).

666574399 is an equidigital number, since it uses as much as digits as its factorization.

666574399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7348320, while the sum is 55.

The square root of 666574399 is about 25818.1021572075. The cubic root of 666574399 is about 873.5401612613.

The spelling of 666574399 in words is "six hundred sixty-six million, five hundred seventy-four thousand, three hundred ninety-nine".