21022055421 has 8 divisors (see below), whose sum is σ = 28035353280. Its totient is φ = 14011730592.

The previous prime is 21022055413. The next prime is 21022055423. The reversal of 21022055421 is 12455022012.

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

It is not a de Polignac number, because 21022055421 - 2³ = 21022055413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21022055391 and 21022055400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022055423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 726705 + ... + 755078.

It is an arithmetic number, because the mean of its divisors is an integer number (3504419160).

Almost surely, 2^21022055421 is an apocalyptic number.

It is an amenable number.

21022055421 is a deficient number, since it is larger than the sum of its proper divisors (7013297859).

21022055421 is a wasteful number, since it uses less digits than its factorization.

21022055421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1486515.

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 21022055421 its reverse (12455022012), we get a palindrome (33477077433).

The spelling of 21022055421 in words is "twenty-one billion, twenty-two million, fifty-five thousand, four hundred twenty-one".