645434434547 has 32 divisors (see below), whose sum is σ = 770623552512. Its totient is φ = 529073161344.

The previous prime is 645434434501. The next prime is 645434434573. The reversal of 645434434547 is 745434434546.

It is not a de Polignac number, because 645434434547 - 2⁶ = 645434434483 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645434434247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7727573 + ... + 7810649.

It is an arithmetic number, because the mean of its divisors is an integer number (24081986016).

Almost surely, 2^645434434547 is an apocalyptic number.

645434434547 is a deficient number, since it is larger than the sum of its proper divisors (125189117965).

645434434547 is a wasteful number, since it uses less digits than its factorization.

645434434547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83667.

The product of its digits is 38707200, while the sum is 53.

Subtracting 645434434547 from its reverse (745434434546), we obtain a palindrome (99999999999).

The spelling of 645434434547 in words is "six hundred forty-five billion, four hundred thirty-four million, four hundred thirty-four thousand, five hundred forty-seven".