1251141821 has 2 divisors, whose sum is σ = 1251141822. Its totient is φ = 1251141820.

The previous prime is 1251141767. The next prime is 1251141823. The reversal of 1251141821 is 1281411521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 828633796 + 422508025 = 28786^2 + 20555^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251141821 - 2¹⁰ = 1251140797 is a prime.

Together with 1251141823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1251141823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625570910 + 625570911.

It is an arithmetic number, because the mean of its divisors is an integer number (625570911).

Almost surely, 2^1251141821 is an apocalyptic number.

It is an amenable number.

1251141821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251141821 is an equidigital number, since it uses as much as digits as its factorization.

1251141821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 640, while the sum is 26.

The square root of 1251141821 is about 35371.4831608741. The cubic root of 1251141821 is about 1077.5452423658.

The spelling of 1251141821 in words is "one billion, two hundred fifty-one million, one hundred forty-one thousand, eight hundred twenty-one".