11658921 has 4 divisors (see below), whose sum is σ = 15545232. Its totient is φ = 7772612.

The previous prime is 11658919. The next prime is 11658929. The reversal of 11658921 is 12985611.

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: 12985611 = 3 ⋅4328537.

It is a cyclic number.

It is not a de Polignac number, because 11658921 - 2¹ = 11658919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11658929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1943151 + ... + 1943156.

It is an arithmetic number, because the mean of its divisors is an integer number (3886308).

Almost surely, 2^11658921 is an apocalyptic number.

It is an amenable number.

11658921 is a deficient number, since it is larger than the sum of its proper divisors (3886311).

11658921 is an equidigital number, since it uses as much as digits as its factorization.

11658921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3886310.

The product of its digits is 4320, while the sum is 33.

The square root of 11658921 is about 3414.5162175629. The cubic root of 11658921 is about 226.7528668203.

The spelling of 11658921 in words is "eleven million, six hundred fifty-eight thousand, nine hundred twenty-one".