645244554042 has 128 divisors (see below), whose sum is σ = 1576681943040. Its totient is φ = 193975560000.

The previous prime is 645244554013. The next prime is 645244554049. The reversal of 645244554042 is 240455442546.

645244554042 is a `hidden beast` number, since 6 + 4 + 5 + 24 + 45 + 540 + 42 = 666.

645244554042 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (645244554049) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 73813792 + ... + 73822532.

It is an arithmetic number, because the mean of its divisors is an integer number (12317827680).

Almost surely, 2^645244554042 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645244554042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (788340971520).

645244554042 is an abundant number, since it is smaller than the sum of its proper divisors (931437388998).

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

645244554042 is a wasteful number, since it uses less digits than its factorization.

645244554042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9737 (or 9731 counting only the distinct ones).

The product of its (nonzero) digits is 3072000, while the sum is 45.

Adding to 645244554042 its reverse (240455442546), we get a palindrome (885699996588).

The spelling of 645244554042 in words is "six hundred forty-five billion, two hundred forty-four million, five hundred fifty-four thousand, forty-two".