645059 has 4 divisors (see below), whose sum is σ = 646704. Its totient is φ = 643416.

The previous prime is 645049. The next prime is 645067. The reversal of 645059 is 950546.

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, and also an emirpimes, since its reverse is a distinct semiprime: 950546 = 2 ⋅475273.

It is a cyclic number.

It is not a de Polignac number, because 645059 - 2¹² = 640963 is a prime.

It is a super-2 number, since 2×645059² = 832202226962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645019) 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, 149 + ... + 1145.

It is an arithmetic number, because the mean of its divisors is an integer number (161676).

2⁶⁴⁵⁰⁵⁹ is an apocalyptic number.

645059 is a deficient number, since it is larger than the sum of its proper divisors (1645).

645059 is an equidigital number, since it uses as much as digits as its factorization.

645059 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 645059 is about 803.1556511661. The cubic root of 645059 is about 86.4038603528.

The spelling of 645059 in words is "six hundred forty-five thousand, fifty-nine".