645562 has 4 divisors (see below), whose sum is σ = 968346. Its totient is φ = 322780.

The previous prime is 645529. The next prime is 645571. The reversal of 645562 is 265546.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 625681 + 19881 = 791^2 + 141^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 645562.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161389 + ... + 161392.

2⁶⁴⁵⁵⁶² is an apocalyptic number.

645562 is a deficient number, since it is larger than the sum of its proper divisors (322784).

645562 is a wasteful number, since it uses less digits than its factorization.

645562 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322783.

The product of its digits is 7200, while the sum is 28.

The square root of 645562 is about 803.4687299454. The cubic root of 645562 is about 86.4263130018.

It can be divided in two parts, 6 and 45562, that multiplied together give a palindrome (273372).

The spelling of 645562 in words is "six hundred forty-five thousand, five hundred sixty-two".