667398399 has 24 divisors (see below), whose sum is σ = 923178240. Its totient is φ = 428802192.

The previous prime is 667398379. The next prime is 667398409. The reversal of 667398399 is 993893766.

It is a happy number.

It is not a de Polignac number, because 667398399 - 2²⁵ = 633843967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667398379) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 437452 + ... + 438974.

It is an arithmetic number, because the mean of its divisors is an integer number (38465760).

Almost surely, 2^667398399 is an apocalyptic number.

667398399 is a deficient number, since it is larger than the sum of its proper divisors (255779841).

667398399 is a wasteful number, since it uses less digits than its factorization.

667398399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1691 (or 1648 counting only the distinct ones).

The product of its digits is 13226976, while the sum is 60.

The square root of 667398399 is about 25834.0550243279. The cubic root of 667398399 is about 873.8999614077.

The spelling of 667398399 in words is "six hundred sixty-seven million, three hundred ninety-eight thousand, three hundred ninety-nine".