1251409 has 2 divisors, whose sum is σ = 1251410. Its totient is φ = 1251408.

The previous prime is 1251329. The next prime is 1251427. The reversal of 1251409 is 9041521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1113025 + 138384 = 1055^2 + 372^2 .

It is an emirp because it is prime and its reverse (9041521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1251409 - 2¹¹ = 1249361 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1251409.

It is not a weakly prime, because it can be changed into another prime (1251109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625704 + 625705.

It is an arithmetic number, because the mean of its divisors is an integer number (625705).

2^1251409 is an apocalyptic number.

It is an amenable number.

1251409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251409 is an equidigital number, since it uses as much as digits as its factorization.

1251409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 1251409 is about 1118.6639352370. The cubic root of 1251409 is about 107.7621939498.

The spelling of 1251409 in words is "one million, two hundred fifty-one thousand, four hundred nine".