6531121251 has 12 divisors (see below), whose sum is σ = 9988773912. Its totient is φ = 4097958336.

The previous prime is 6531121243. The next prime is 6531121271. The reversal of 6531121251 is 1521211356.

6531121251 is a `hidden beast` number, since 6 + 531 + 1 + 2 + 125 + 1 = 666.

It is not a de Polignac number, because 6531121251 - 2³ = 6531121243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6531121231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21343381 + ... + 21343686.

It is an arithmetic number, because the mean of its divisors is an integer number (832397826).

Almost surely, 2^6531121251 is an apocalyptic number.

6531121251 is a deficient number, since it is larger than the sum of its proper divisors (3457652661).

6531121251 is a wasteful number, since it uses less digits than its factorization.

6531121251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42687090 (or 42687087 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 6531121251 is about 80815.3528173948. The cubic root of 6531121251 is about 1869.2293097050.

The spelling of 6531121251 in words is "six billion, five hundred thirty-one million, one hundred twenty-one thousand, two hundred fifty-one".