21556341 has 8 divisors (see below), whose sum is σ = 31935360. Its totient is φ = 14370876.

The previous prime is 21556321. The next prime is 21556349. The reversal of 21556341 is 14365512.

21556341 is a `hidden beast` number, since 21 + 5 + 5 + 634 + 1 = 666.

It is not a de Polignac number, because 21556341 - 2⁹ = 21555829 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 798383 = 21556341 / (2 + 1 + 5 + 5 + 6 + 3 + 4 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21556349) 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, 399165 + ... + 399218.

It is an arithmetic number, because the mean of its divisors is an integer number (3991920).

Almost surely, 2^21556341 is an apocalyptic number.

It is an amenable number.

21556341 is a deficient number, since it is larger than the sum of its proper divisors (10379019).

21556341 is an equidigital number, since it uses as much as digits as its factorization.

21556341 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798392 (or 798386 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 21556341 is about 4642.8806790612. The cubic root of 21556341 is about 278.3075672261.

The spelling of 21556341 in words is "twenty-one million, five hundred fifty-six thousand, three hundred forty-one".