644497 has 8 divisors (see below), whose sum is σ = 752000. Its totient is φ = 552132.

The previous prime is 644491. The next prime is 644507. The reversal of 644497 is 794446.

644497 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 644497 - 2³ = 644489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 597 + ... + 1282.

It is an arithmetic number, because the mean of its divisors is an integer number (94000).

2⁶⁴⁴⁴⁹⁷ is an apocalyptic number.

644497 is the 464-th hex number.

It is an amenable number.

644497 is a deficient number, since it is larger than the sum of its proper divisors (107503).

644497 is an equidigital number, since it uses as much as digits as its factorization.

644497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1900 (or 1886 counting only the distinct ones).

The product of its digits is 24192, while the sum is 34.

The square root of 644497 is about 802.8057050121. The cubic root of 644497 is about 86.3787602826.

The spelling of 644497 in words is "six hundred forty-four thousand, four hundred ninety-seven".