21551422 has 8 divisors (see below), whose sum is σ = 32857272. Its totient is φ = 10599000.

The previous prime is 21551407. The next prime is 21551423. The reversal of 21551422 is 22415512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21551393 and 21551402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551423) 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 3 ways as a sum of consecutive naturals, for example, 88204 + ... + 88447.

It is an arithmetic number, because the mean of its divisors is an integer number (4107159).

Almost surely, 2^21551422 is an apocalyptic number.

21551422 is a deficient number, since it is larger than the sum of its proper divisors (11305850).

21551422 is a wasteful number, since it uses less digits than its factorization.

21551422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176714.

The product of its digits is 800, while the sum is 22.

The square root of 21551422 is about 4642.3509130612. The cubic root of 21551422 is about 278.2863963625.

Adding to 21551422 its reverse (22415512), we get a palindrome (43966934).

The spelling of 21551422 in words is "twenty-one million, five hundred fifty-one thousand, four hundred twenty-two".