1251791 has 2 divisors, whose sum is σ = 1251792. Its totient is φ = 1251790.

The previous prime is 1251787. The next prime is 1251797. The reversal of 1251791 is 1971521.

It is a weak prime.

It is an emirp because it is prime and its reverse (1971521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1251791 - 2² = 1251787 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1251791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1251797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625895 + 625896.

It is an arithmetic number, because the mean of its divisors is an integer number (625896).

2^1251791 is an apocalyptic number.

1251791 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251791 is an equidigital number, since it uses as much as digits as its factorization.

1251791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 630, while the sum is 26.

The square root of 1251791 is about 1118.8346616011. The cubic root of 1251791 is about 107.7731578500.

The spelling of 1251791 in words is "one million, two hundred fifty-one thousand, seven hundred ninety-one".