21273441 has 16 divisors (see below), whose sum is σ = 32863104. Its totient is φ = 11988864.

The previous prime is 21273437. The next prime is 21273449. The reversal of 21273441 is 14437212.

It is a happy number.

It is not a de Polignac number, because 21273441 - 2² = 21273437 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21273449) 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 15 ways as a sum of consecutive naturals, for example, 5406 + ... + 8471.

It is an arithmetic number, because the mean of its divisors is an integer number (2053944).

Almost surely, 2^21273441 is an apocalyptic number.

21273441 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21273441 is a deficient number, since it is larger than the sum of its proper divisors (11589663).

21273441 is a wasteful number, since it uses less digits than its factorization.

21273441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13960.

The product of its digits is 1344, while the sum is 24.

The square root of 21273441 is about 4612.3140612929. The cubic root of 21273441 is about 277.0847225714.

The spelling of 21273441 in words is "twenty-one million, two hundred seventy-three thousand, four hundred forty-one".