645113131 has 32 divisors (see below), whose sum is σ = 758661120. Its totient is φ = 543628800.

The previous prime is 645113123. The next prime is 645113197. The reversal of 645113131 is 131311546.

It is not a de Polignac number, because 645113131 - 2³ = 645113123 is a prime.

It is a super-2 number, since 2×645113131² = 832341903577246322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645113096 and 645113105.

It is not an unprimeable number, because it can be changed into a prime (645113431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 731811 + ... + 732691.

It is an arithmetic number, because the mean of its divisors is an integer number (23708160).

Almost surely, 2^645113131 is an apocalyptic number.

645113131 is a deficient number, since it is larger than the sum of its proper divisors (113547989).

645113131 is a wasteful number, since it uses less digits than its factorization.

645113131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027.

The product of its digits is 1080, while the sum is 25.

The square root of 645113131 is about 25399.0773651328. The cubic root of 645113131 is about 864.0627718418.

Adding to 645113131 its reverse (131311546), we get a palindrome (776424677).

The spelling of 645113131 in words is "six hundred forty-five million, one hundred thirteen thousand, one hundred thirty-one".