645611422 has 4 divisors (see below), whose sum is σ = 968417136. Its totient is φ = 322805710.

The previous prime is 645611413. The next prime is 645611467. The reversal of 645611422 is 224116546.

It is a happy number.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161402854 + ... + 161402857.

It is an arithmetic number, because the mean of its divisors is an integer number (242104284).

Almost surely, 2^645611422 is an apocalyptic number.

645611422 is a deficient number, since it is larger than the sum of its proper divisors (322805714).

645611422 is a wasteful number, since it uses less digits than its factorization.

645611422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322805713.

The product of its digits is 11520, while the sum is 31.

The square root of 645611422 is about 25408.8847059449. The cubic root of 645611422 is about 864.2851844569.

Adding to 645611422 its reverse (224116546), we get a palindrome (869727968).

The spelling of 645611422 in words is "six hundred forty-five million, six hundred eleven thousand, four hundred twenty-two".