21931441 has 8 divisors (see below), whose sum is σ = 25139520. Its totient is φ = 18742128.

The previous prime is 21931439. The next prime is 21931447. The reversal of 21931441 is 14413912.

It is a happy number.

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 21931441 - 2¹ = 21931439 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21931447) 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 7 ways as a sum of consecutive naturals, for example, 2086 + ... + 6943.

It is an arithmetic number, because the mean of its divisors is an integer number (3142440).

Almost surely, 2^21931441 is an apocalyptic number.

It is an amenable number.

21931441 is a deficient number, since it is larger than the sum of its proper divisors (3208079).

21931441 is an equidigital number, since it uses as much as digits as its factorization.

21931441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9383.

The product of its digits is 864, while the sum is 25.

The square root of 21931441 is about 4683.1016431421. The cubic root of 21931441 is about 279.9125619835.

The spelling of 21931441 in words is "twenty-one million, nine hundred thirty-one thousand, four hundred forty-one".