645575455121 has 4 divisors (see below), whose sum is σ = 645682860144. Its totient is φ = 645468050100.

The previous prime is 645575455117. The next prime is 645575455123. The reversal of 645575455121 is 121554575546.

645575455121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 121554575546 = 2 ⋅60777287773.

It is a cyclic number.

It is not a de Polignac number, because 645575455121 - 2² = 645575455117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645575455121.

It is not an unprimeable number, because it can be changed into a prime (645575455123) 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, 53693495 + ... + 53705516.

It is an arithmetic number, because the mean of its divisors is an integer number (161420715036).

Almost surely, 2^645575455121 is an apocalyptic number.

It is an amenable number.

645575455121 is a deficient number, since it is larger than the sum of its proper divisors (107405023).

645575455121 is a wasteful number, since it uses less digits than its factorization.

645575455121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107405022.

The product of its digits is 4200000, while the sum is 50.

The spelling of 645575455121 in words is "six hundred forty-five billion, five hundred seventy-five million, four hundred fifty-five thousand, one hundred twenty-one".