664051 has 6 divisors (see below), whose sum is σ = 687156. Its totient is φ = 641700.

The previous prime is 664043. The next prime is 664061. The reversal of 664051 is 150466.

664051 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 664051 - 2³ = 664043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664061) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 616 + ... + 1306.

It is an arithmetic number, because the mean of its divisors is an integer number (114526).

2⁶⁶⁴⁰⁵¹ is an apocalyptic number.

664051 is a deficient number, since it is larger than the sum of its proper divisors (23105).

664051 is an equidigital number, since it uses as much as digits as its factorization.

664051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753 (or 722 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 664051 is about 814.8932445419. The cubic root of 664051 is about 87.2436469623.

The spelling of 664051 in words is "six hundred sixty-four thousand, fifty-one".