645321433562 has 16 divisors (see below), whose sum is σ = 1070616433992. Its totient is φ = 289790913600.

The previous prime is 645321433541. The next prime is 645321433597. The reversal of 645321433562 is 265334123546.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 561673803601 + 83647629961 = 749449^2 + 289219^2 .

It is a super-2 number, since 2×645321433562² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 335405189 + ... + 335407112.

Almost surely, 2^645321433562 is an apocalyptic number.

645321433562 is a deficient number, since it is larger than the sum of its proper divisors (425295000430).

645321433562 is a wasteful number, since it uses less digits than its factorization.

645321433562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670812353.

The product of its digits is 1555200, while the sum is 44.

The spelling of 645321433562 in words is "six hundred forty-five billion, three hundred twenty-one million, four hundred thirty-three thousand, five hundred sixty-two".