1251399 has 4 divisors (see below), whose sum is σ = 1668536. Its totient is φ = 834264.

The previous prime is 1251329. The next prime is 1251409. The reversal of 1251399 is 9931521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9931521 = 3 ⋅3310507.

It is not a de Polignac number, because 1251399 - 2¹² = 1247303 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208564 + ... + 208569.

It is an arithmetic number, because the mean of its divisors is an integer number (417134).

2^1251399 is an apocalyptic number.

1251399 is a deficient number, since it is larger than the sum of its proper divisors (417137).

1251399 is an equidigital number, since it uses as much as digits as its factorization.

1251399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417136.

The product of its digits is 2430, while the sum is 30.

The square root of 1251399 is about 1118.6594656105. The cubic root of 1251399 is about 107.7619069068.

The spelling of 1251399 in words is "one million, two hundred fifty-one thousand, three hundred ninety-nine".