664213439 has 4 divisors (see below), whose sum is σ = 664272960. Its totient is φ = 664153920.

The previous prime is 664213373. The next prime is 664213483. The reversal of 664213439 is 934312466.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 664213439 - 2¹⁶ = 664147903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664213639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7442 + ... + 37199.

It is an arithmetic number, because the mean of its divisors is an integer number (166068240).

Almost surely, 2^664213439 is an apocalyptic number.

664213439 is a deficient number, since it is larger than the sum of its proper divisors (59521).

664213439 is a wasteful number, since it uses less digits than its factorization.

664213439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59520.

The product of its digits is 93312, while the sum is 38.

The square root of 664213439 is about 25772.3386404882. The cubic root of 664213439 is about 872.5076017871.

The spelling of 664213439 in words is "six hundred sixty-four million, two hundred thirteen thousand, four hundred thirty-nine".