1251111493 has 2 divisors, whose sum is σ = 1251111494. Its totient is φ = 1251111492.

The previous prime is 1251111469. The next prime is 1251111523. The reversal of 1251111493 is 3941111521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 954686404 + 296425089 = 30898^2 + 17217^2 .

It is an emirp because it is prime and its reverse (3941111521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1251111493 - 2¹⁷ = 1250980421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1251111443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625555746 + 625555747.

It is an arithmetic number, because the mean of its divisors is an integer number (625555747).

Almost surely, 2^1251111493 is an apocalyptic number.

It is an amenable number.

1251111493 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251111493 is an equidigital number, since it uses as much as digits as its factorization.

1251111493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 28.

The square root of 1251111493 is about 35371.0544513448. The cubic root of 1251111493 is about 1077.5365356374.

Adding to 1251111493 its sum of digits (28), we get a palindrome (1251111521).

The spelling of 1251111493 in words is "one billion, two hundred fifty-one million, one hundred eleven thousand, four hundred ninety-three".