1153861 has 4 divisors (see below), whose sum is σ = 1156012. Its totient is φ = 1151712.

The previous prime is 1153853. The next prime is 1153871. The reversal of 1153861 is 1683511.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1683511 = 157 ⋅10723.

It can be written as a sum of positive squares in 2 ways, for example, as 591361 + 562500 = 769^2 + 750^2 .

It is a cyclic number.

It is not a de Polignac number, because 1153861 - 2³ = 1153853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1153811) 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, 475 + ... + 1591.

It is an arithmetic number, because the mean of its divisors is an integer number (289003).

2^1153861 is an apocalyptic number.

It is an amenable number.

1153861 is a deficient number, since it is larger than the sum of its proper divisors (2151).

1153861 is a wasteful number, since it uses less digits than its factorization.

1153861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2150.

The product of its digits is 720, while the sum is 25.

The square root of 1153861 is about 1074.1792215455. The cubic root of 1153861 is about 104.8860744697.

The spelling of 1153861 in words is "one million, one hundred fifty-three thousand, eight hundred sixty-one".