21221551026530 has 8 divisors (see below), whose sum is σ = 38198791847772. Its totient is φ = 8488620410608.

The previous prime is 21221551026509. The next prime is 21221551026539. The reversal of 21221551026530 is 3562015512212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20676182069449 + 545368957081 = 4547107^2 + 738491^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21221551026539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1061077551317 + ... + 1061077551336.

Almost surely, 2^{21221551026530} is an apocalyptic number.

21221551026530 is a deficient number, since it is larger than the sum of its proper divisors (16977240821242).

21221551026530 is a wasteful number, since it uses less digits than its factorization.

21221551026530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122155102660.

The product of its (nonzero) digits is 36000, while the sum is 35.

Adding to 21221551026530 its reverse (3562015512212), we get a palindrome (24783566538742).

The spelling of 21221551026530 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred fifty-one million, twenty-six thousand, five hundred thirty".