667405399 has 2 divisors, whose sum is σ = 667405400. Its totient is φ = 667405398.

The previous prime is 667405373. The next prime is 667405429. The reversal of 667405399 is 993504766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 667405399 - 2⁵ = 667405367 is a prime.

It is a super-2 number, since 2×667405399² = 890859933228698402, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667409399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333702699 + 333702700.

It is an arithmetic number, because the mean of its divisors is an integer number (333702700).

Almost surely, 2^667405399 is an apocalyptic number.

667405399 is a deficient number, since it is larger than the sum of its proper divisors (1).

667405399 is an equidigital number, since it uses as much as digits as its factorization.

667405399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1224720, while the sum is 49.

The square root of 667405399 is about 25834.1905040588. The cubic root of 667405399 is about 873.9030166934.

The spelling of 667405399 in words is "six hundred sixty-seven million, four hundred five thousand, three hundred ninety-nine".