1991253 has 16 divisors (see below), whose sum is σ = 2935296. Its totient is φ = 1190640.

The previous prime is 1991251. The next prime is 1991267. The reversal of 1991253 is 3521991.

It is not a de Polignac number, because 1991253 - 2¹ = 1991251 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1991253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991251) 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 15 ways as a sum of consecutive naturals, for example, 2376 + ... + 3102.

It is an arithmetic number, because the mean of its divisors is an integer number (183456).

2^1991253 is an apocalyptic number.

It is an amenable number.

1991253 is a deficient number, since it is larger than the sum of its proper divisors (944043).

1991253 is a wasteful number, since it uses less digits than its factorization.

1991253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824.

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

The square root of 1991253 is about 1411.1176421546. The cubic root of 1991253 is about 125.8081610783.

The spelling of 1991253 in words is "one million, nine hundred ninety-one thousand, two hundred fifty-three".