21554227 has 6 divisors (see below), whose sum is σ = 22748748. Its totient is φ = 20419452.

The previous prime is 21554219. The next prime is 21554231. The reversal of 21554227 is 72245512.

It is not a de Polignac number, because 21554227 - 2³ = 21554219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21554195 and 21554204.

It is not an unprimeable number, because it can be changed into a prime (21554237) 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 5 ways as a sum of consecutive naturals, for example, 29493 + ... + 30214.

It is an arithmetic number, because the mean of its divisors is an integer number (3791458).

Almost surely, 2^21554227 is an apocalyptic number.

21554227 is a deficient number, since it is larger than the sum of its proper divisors (1194521).

21554227 is an equidigital number, since it uses as much as digits as its factorization.

21554227 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59745 (or 59726 counting only the distinct ones).

The product of its digits is 5600, while the sum is 28.

The square root of 21554227 is about 4642.6530130950. The cubic root of 21554227 is about 278.2984691850.

Adding to 21554227 its reverse (72245512), we get a palindrome (93799739).

The spelling of 21554227 in words is "twenty-one million, five hundred fifty-four thousand, two hundred twenty-seven".