21256421122 has 8 divisors (see below), whose sum is σ = 32005866816. Its totient is φ = 10587798852.

The previous prime is 21256421089. The next prime is 21256421141. The reversal of 21256421122 is 22112465212.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20205198 + ... + 20206249.

It is an arithmetic number, because the mean of its divisors is an integer number (4000733352).

Almost surely, 2^21256421122 is an apocalyptic number.

21256421122 is a deficient number, since it is larger than the sum of its proper divisors (10749445694).

21256421122 is a wasteful number, since it uses less digits than its factorization.

21256421122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40411712.

The product of its digits is 3840, while the sum is 28.

Adding to 21256421122 its reverse (22112465212), we get a palindrome (43368886334).

The spelling of 21256421122 in words is "twenty-one billion, two hundred fifty-six million, four hundred twenty-one thousand, one hundred twenty-two".