651538527221 has 2 divisors, whose sum is σ = 651538527222. Its totient is φ = 651538527220.

The previous prime is 651538527193. The next prime is 651538527247. The reversal of 651538527221 is 122725835156.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 642219520996 + 9319006225 = 801386^2 + 96535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-651538527221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651538527421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325769263610 + 325769263611.

It is an arithmetic number, because the mean of its divisors is an integer number (325769263611).

Almost surely, 2^651538527221 is an apocalyptic number.

It is an amenable number.

651538527221 is a deficient number, since it is larger than the sum of its proper divisors (1).

651538527221 is an equidigital number, since it uses as much as digits as its factorization.

651538527221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008000, while the sum is 47.

The spelling of 651538527221 in words is "six hundred fifty-one billion, five hundred thirty-eight million, five hundred twenty-seven thousand, two hundred twenty-one".