645426 has 24 divisors (see below), whose sum is σ = 1460160. Its totient is φ = 205656.

The previous prime is 645419. The next prime is 645431. The reversal of 645426 is 624546.

It is a happy number.

645426 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 645426.

It is an unprimeable number.

645426 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 366 + ... + 1193.

It is an arithmetic number, because the mean of its divisors is an integer number (60840).

2⁶⁴⁵⁴²⁶ is an apocalyptic number.

645426 is an abundant number, since it is smaller than the sum of its proper divisors (814734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645426 is a wasteful number, since it uses less digits than its factorization.

645426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1590 (or 1587 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 645426 is about 803.3840924489. The cubic root of 645426 is about 86.4202434562.

The spelling of 645426 in words is "six hundred forty-five thousand, four hundred twenty-six".