645103252042 has 4 divisors (see below), whose sum is σ = 967654878066. Its totient is φ = 322551626020.

The previous prime is 645103251997. The next prime is 645103252043. The reversal of 645103252042 is 240252301546.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 538343570961 + 106759681081 = 733719^2 + 326741^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645103251989 and 645103252007.

It is not an unprimeable number, because it can be changed into a prime (645103252043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161275813009 + ... + 161275813012.

Almost surely, 2^645103252042 is an apocalyptic number.

645103252042 is a deficient number, since it is larger than the sum of its proper divisors (322551626024).

645103252042 is a wasteful number, since it uses less digits than its factorization.

645103252042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322551626023.

The product of its (nonzero) digits is 57600, while the sum is 34.

Adding to 645103252042 its reverse (240252301546), we get a palindrome (885355553588).

The spelling of 645103252042 in words is "six hundred forty-five billion, one hundred three million, two hundred fifty-two thousand, forty-two".