645122229 has 4 divisors (see below), whose sum is σ = 860162976. Its totient is φ = 430081484.

The previous prime is 645122227. The next prime is 645122251. The reversal of 645122229 is 922221546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645122229 - 2¹ = 645122227 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645122229.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645122227) 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, 107520369 + ... + 107520374.

It is an arithmetic number, because the mean of its divisors is an integer number (215040744).

Almost surely, 2^645122229 is an apocalyptic number.

It is an amenable number.

645122229 is a deficient number, since it is larger than the sum of its proper divisors (215040747).

645122229 is a wasteful number, since it uses less digits than its factorization.

645122229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215040746.

The product of its digits is 17280, while the sum is 33.

The square root of 645122229 is about 25399.2564654952. The cubic root of 645122229 is about 864.0668337682.

It can be divided in two parts, 6451 and 22229, that added together give a triangular number (28680 = T₂₃₉).

The spelling of 645122229 in words is "six hundred forty-five million, one hundred twenty-two thousand, two hundred twenty-nine".