645051 has 12 divisors (see below), whose sum is σ = 945896. Its totient is φ = 390720.

The previous prime is 645049. The next prime is 645067. The reversal of 645051 is 150546.

It is a happy number.

It is not a de Polignac number, because 645051 - 2¹ = 645049 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645051.

It is not an unprimeable number, because it can be changed into a prime (645011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 526 + ... + 1251.

2⁶⁴⁵⁰⁵¹ is an apocalyptic number.

645051 is a deficient number, since it is larger than the sum of its proper divisors (300845).

645051 is a wasteful number, since it uses less digits than its factorization.

645051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1802 (or 1791 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 645051 is about 803.1506707960. The cubic root of 645051 is about 86.4035031587.

Adding to 645051 its reverse (150546), we get a palindrome (795597).

It can be divided in two parts, 64 and 5051, that added together give a palindrome (5115).

The spelling of 645051 in words is "six hundred forty-five thousand, fifty-one".