645161297420 has 24 divisors (see below), whose sum is σ = 1354918595184. Its totient is φ = 258049305536.

The previous prime is 645161297413. The next prime is 645161297423. The reversal of 645161297420 is 24792161546.

It is not an unprimeable number, because it can be changed into a prime (645161297423) by changing a digit.

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, 599942 + ... + 1284621.

It is an arithmetic number, because the mean of its divisors is an integer number (56454941466).

Almost surely, 2^645161297420 is an apocalyptic number.

It is an amenable number.

645161297420 is an abundant number, since it is smaller than the sum of its proper divisors (709757297764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645161297420 is a wasteful number, since it uses less digits than its factorization.

645161297420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1901689 (or 1901687 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 47.

The spelling of 645161297420 in words is "six hundred forty-five billion, one hundred sixty-one million, two hundred ninety-seven thousand, four hundred twenty".