645424145441 has 4 divisors (see below), whose sum is σ = 673486064832. Its totient is φ = 617362226052.

The previous prime is 645424145341. The next prime is 645424145447. The reversal of 645424145441 is 144541424546.

It is a happy number.

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 645424145441 - 2³⁸ = 370546238497 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645424145392 and 645424145401.

It is not an unprimeable number, because it can be changed into a prime (645424145447) 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, 14030959661 + ... + 14030959706.

It is an arithmetic number, because the mean of its divisors is an integer number (168371516208).

Almost surely, 2^645424145441 is an apocalyptic number.

It is an amenable number.

645424145441 is a deficient number, since it is larger than the sum of its proper divisors (28061919391).

645424145441 is a wasteful number, since it uses less digits than its factorization.

645424145441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28061919390.

The product of its digits is 1228800, while the sum is 44.

Adding to 645424145441 its reverse (144541424546), we get a palindrome (789965569987).

The spelling of 645424145441 in words is "six hundred forty-five billion, four hundred twenty-four million, one hundred forty-five thousand, four hundred forty-one".