1153661 has 4 divisors (see below), whose sum is σ = 1214400. Its totient is φ = 1092924.

The previous prime is 1153643. The next prime is 1153681. The reversal of 1153661 is 1663511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1663511 = 53 ⋅31387.

It is a cyclic number.

It is not a de Polignac number, because 1153661 - 2⁶ = 1153597 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 (1153681) 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, 30341 + ... + 30378.

It is an arithmetic number, because the mean of its divisors is an integer number (303600).

2^1153661 is an apocalyptic number.

It is an amenable number.

1153661 is a deficient number, since it is larger than the sum of its proper divisors (60739).

1153661 is an equidigital number, since it uses as much as digits as its factorization.

1153661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60738.

The product of its digits is 540, while the sum is 23.

The square root of 1153661 is about 1074.0861231763. The cubic root of 1153661 is about 104.8800141132.

The spelling of 1153661 in words is "one million, one hundred fifty-three thousand, six hundred sixty-one".