645027131 has 12 divisors (see below), whose sum is σ = 751018320. Its totient is φ = 552378960.

The previous prime is 645027041. The next prime is 645027161. The reversal of 645027131 is 131720546.

It is a de Polignac number, because none of the positive numbers 2^k-645027131 is a prime.

It is a super-2 number, since 2×645027131² = 832119999452182322, 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 = 645027094 and 645027103.

It is not an unprimeable number, because it can be changed into a prime (645027161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 54866 + ... + 65576.

It is an arithmetic number, because the mean of its divisors is an integer number (62584860).

Almost surely, 2^645027131 is an apocalyptic number.

645027131 is a deficient number, since it is larger than the sum of its proper divisors (105991189).

645027131 is a wasteful number, since it uses less digits than its factorization.

645027131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11954 (or 11947 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 645027131 is about 25397.3843338246. The cubic root of 645027131 is about 864.0243740802.

Adding to 645027131 its reverse (131720546), we get a palindrome (776747677).

The spelling of 645027131 in words is "six hundred forty-five million, twenty-seven thousand, one hundred thirty-one".