664426 has 8 divisors (see below), whose sum is σ = 1139040. Its totient is φ = 284748.

The previous prime is 664421. The next prime is 664427. The reversal of 664426 is 624466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 664394 and 664403.

It is not an unprimeable number, because it can be changed into a prime (664421) 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, 23716 + ... + 23743.

It is an arithmetic number, because the mean of its divisors is an integer number (142380).

2⁶⁶⁴⁴²⁶ is an apocalyptic number.

664426 is a deficient number, since it is larger than the sum of its proper divisors (474614).

664426 is a wasteful number, since it uses less digits than its factorization.

664426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47468.

The product of its digits is 6912, while the sum is 28.

The square root of 664426 is about 815.1233035560. The cubic root of 664426 is about 87.2600664899.

It can be divided in two parts, 6644 and 26, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 664426 in words is "six hundred sixty-four thousand, four hundred twenty-six".