6521551249 has 2 divisors, whose sum is σ = 6521551250. Its totient is φ = 6521551248.

The previous prime is 6521551247. The next prime is 6521551277. The reversal of 6521551249 is 9421551256.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5242773649 + 1278777600 = 72407^2 + 35760^2 .

It is a cyclic number.

It is not a de Polignac number, because 6521551249 - 2¹ = 6521551247 is a prime.

Together with 6521551247, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6521551247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3260775624 + 3260775625.

It is an arithmetic number, because the mean of its divisors is an integer number (3260775625).

Almost surely, 2^6521551249 is an apocalyptic number.

It is an amenable number.

6521551249 is a deficient number, since it is larger than the sum of its proper divisors (1).

6521551249 is an equidigital number, since it uses as much as digits as its factorization.

6521551249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108000, while the sum is 40.

The square root of 6521551249 is about 80756.1220527583. The cubic root of 6521551249 is about 1868.3158742743.

The spelling of 6521551249 in words is "six billion, five hundred twenty-one million, five hundred fifty-one thousand, two hundred forty-nine".