645152442031 has 4 divisors (see below), whose sum is σ = 648495200992. Its totient is φ = 641809683072.

The previous prime is 645152442029. The next prime is 645152442047. The reversal of 645152442031 is 130244251546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130244251546 = 2 ⋅65122125773.

It is a cyclic number.

It is not a de Polignac number, because 645152442031 - 2¹ = 645152442029 is a prime.

It is a super-2 number, since 2×645152442031² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645152442731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1671379191 + ... + 1671379576.

It is an arithmetic number, because the mean of its divisors is an integer number (162123800248).

Almost surely, 2^645152442031 is an apocalyptic number.

645152442031 is a deficient number, since it is larger than the sum of its proper divisors (3342758961).

645152442031 is a wasteful number, since it uses less digits than its factorization.

645152442031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3342758960.

The product of its (nonzero) digits is 115200, while the sum is 37.

Adding to 645152442031 its reverse (130244251546), we get a palindrome (775396693577).

The spelling of 645152442031 in words is "six hundred forty-five billion, one hundred fifty-two million, four hundred forty-two thousand, thirty-one".