1251324521 has 2 divisors, whose sum is σ = 1251324522. Its totient is φ = 1251324520.

The previous prime is 1251324479. The next prime is 1251324539. The reversal of 1251324521 is 1254231521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1208605225 + 42719296 = 34765^2 + 6536^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251324521 - 2¹⁰ = 1251323497 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1251324421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625662260 + 625662261.

It is an arithmetic number, because the mean of its divisors is an integer number (625662261).

Almost surely, 2^1251324521 is an apocalyptic number.

It is an amenable number.

1251324521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251324521 is an equidigital number, since it uses as much as digits as its factorization.

1251324521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 26.

The square root of 1251324521 is about 35374.0656555053. The cubic root of 1251324521 is about 1077.5976899063.

The spelling of 1251324521 in words is "one billion, two hundred fifty-one million, three hundred twenty-four thousand, five hundred twenty-one".