1240043251021 has 2 divisors, whose sum is σ = 1240043251022. Its totient is φ = 1240043251020.

The previous prime is 1240043251001. The next prime is 1240043251037. The reversal of 1240043251021 is 1201523400421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 899868520996 + 340174730025 = 948614^2 + 583245^2 .

It is a cyclic number.

It is not a de Polignac number, because 1240043251021 - 2⁵ = 1240043250989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1240043251001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620021625510 + 620021625511.

It is an arithmetic number, because the mean of its divisors is an integer number (620021625511).

Almost surely, 2^{1240043251021} is an apocalyptic number.

It is an amenable number.

1240043251021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240043251021 is an equidigital number, since it uses as much as digits as its factorization.

1240043251021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 1240043251021 its reverse (1201523400421), we get a palindrome (2441566651442).

The spelling of 1240043251021 in words is "one trillion, two hundred forty billion, forty-three million, two hundred fifty-one thousand, twenty-one".