1251376381 has 2 divisors, whose sum is σ = 1251376382. Its totient is φ = 1251376380.

The previous prime is 1251376369. The next prime is 1251376397. The reversal of 1251376381 is 1836731521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 690112900 + 561263481 = 26270^2 + 23691^2 .

It is an emirp because it is prime and its reverse (1836731521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1251376381 - 2⁹ = 1251375869 is a prime.

It is a super-2 number, since 2×1251376381² = 3131885693849314322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1251376381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1251376781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625688190 + 625688191.

It is an arithmetic number, because the mean of its divisors is an integer number (625688191).

Almost surely, 2^1251376381 is an apocalyptic number.

It is an amenable number.

1251376381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251376381 is an equidigital number, since it uses as much as digits as its factorization.

1251376381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 37.

The square root of 1251376381 is about 35374.7986708052. The cubic root of 1251376381 is about 1077.6125763841.

The spelling of 1251376381 in words is "one billion, two hundred fifty-one million, three hundred seventy-six thousand, three hundred eighty-one".