1391251 has 4 divisors (see below), whose sum is σ = 1401400. Its totient is φ = 1381104.

The previous prime is 1391239. The next prime is 1391261. The reversal of 1391251 is 1521931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1521931 = 163 ⋅9337.

It is not a de Polignac number, because 1391251 - 2¹⁹ = 866963 is a prime.

It is a Duffinian number.

1391251 is a modest number, since divided by 1251 gives 139 as remainder.

It is not an unprimeable number, because it can be changed into a prime (1391261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4866 + ... + 5143.

It is an arithmetic number, because the mean of its divisors is an integer number (350350).

2^1391251 is an apocalyptic number.

1391251 is a deficient number, since it is larger than the sum of its proper divisors (10149).

1391251 is a wasteful number, since it uses less digits than its factorization.

1391251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10148.

The product of its digits is 270, while the sum is 22.

The square root of 1391251 is about 1179.5130351124. The cubic root of 1391251 is about 111.6353735238.

It can be divided in two parts, 139 and 1251, that multiplied together give a square (173889 = 417²).

The spelling of 1391251 in words is "one million, three hundred ninety-one thousand, two hundred fifty-one".