664351 has 4 divisors (see below), whose sum is σ = 675304. Its totient is φ = 653400.

The previous prime is 664331. The next prime is 664357. The reversal of 664351 is 153466.

664351 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 153466 = 2 ⋅76733.

It is a cyclic number.

It is not a de Polignac number, because 664351 - 2⁵ = 664319 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664357) 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, 5385 + ... + 5506.

It is an arithmetic number, because the mean of its divisors is an integer number (168826).

2⁶⁶⁴³⁵¹ is an apocalyptic number.

664351 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

664351 is the 516-th centered pentagonal number.

664351 is a deficient number, since it is larger than the sum of its proper divisors (10953).

664351 is a wasteful number, since it uses less digits than its factorization.

664351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10952.

The product of its digits is 2160, while the sum is 25.

The square root of 664351 is about 815.0772969480. The cubic root of 664351 is about 87.2567830787.

The spelling of 664351 in words is "six hundred sixty-four thousand, three hundred fifty-one".