21451241 has 12 divisors (see below), whose sum is σ = 25142016. Its totient is φ = 17928480.

The previous prime is 21451237. The next prime is 21451277. The reversal of 21451241 is 14215412.

It is a happy number.

It is not a de Polignac number, because 21451241 - 2² = 21451237 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 (21451201) 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 11 ways as a sum of consecutive naturals, for example, 10856 + ... + 12678.

It is an arithmetic number, because the mean of its divisors is an integer number (2095168).

Almost surely, 2^21451241 is an apocalyptic number.

It is an amenable number.

21451241 is a deficient number, since it is larger than the sum of its proper divisors (3690775).

21451241 is an equidigital number, since it uses as much as digits as its factorization.

21451241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912 (or 1871 counting only the distinct ones).

The product of its digits is 320, while the sum is 20.

The square root of 21451241 is about 4631.5484451747. The cubic root of 21451241 is about 277.8545250987.

Adding to 21451241 its reverse (14215412), we get a palindrome (35666653).

The spelling of 21451241 in words is "twenty-one million, four hundred fifty-one thousand, two hundred forty-one".