1157921 has 4 divisors (see below), whose sum is σ = 1226052. Its totient is φ = 1089792.

The previous prime is 1157899. The next prime is 1157929. The reversal of 1157921 is 1297511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1297511 = 653 ⋅1987.

It can be written as a sum of positive squares in 2 ways, for example, as 616225 + 541696 = 785^2 + 736^2 .

It is a cyclic number.

It is not a de Polignac number, because 1157921 - 2¹⁸ = 895777 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1157929) 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, 34040 + ... + 34073.

It is an arithmetic number, because the mean of its divisors is an integer number (306513).

2^1157921 is an apocalyptic number.

It is an amenable number.

1157921 is a deficient number, since it is larger than the sum of its proper divisors (68131).

1157921 is an equidigital number, since it uses as much as digits as its factorization.

1157921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68130.

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

The square root of 1157921 is about 1076.0673770726. The cubic root of 1157921 is about 105.0089485949.

The spelling of 1157921 in words is "one million, one hundred fifty-seven thousand, nine hundred twenty-one".