11921921 has 8 divisors (see below), whose sum is σ = 13039488. Its totient is φ = 10810000.

The previous prime is 11921867. The next prime is 11921933. The reversal of 11921921 is 12912911.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11921921 - 2¹⁰ = 11920897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11923921) 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 7 ways as a sum of consecutive naturals, for example, 3896 + ... + 6246.

It is an arithmetic number, because the mean of its divisors is an integer number (1629936).

Almost surely, 2^11921921 is an apocalyptic number.

11921921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11921921 is a deficient number, since it is larger than the sum of its proper divisors (1117567).

11921921 is a wasteful number, since it uses less digits than its factorization.

11921921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2823.

The product of its digits is 324, while the sum is 26.

The square root of 11921921 is about 3452.8134904741. The cubic root of 11921921 is about 228.4452224224.

It can be divided in two parts, 1192 and 1921, that added together give a palindrome (3113).

The spelling of 11921921 in words is "eleven million, nine hundred twenty-one thousand, nine hundred twenty-one".