21221522225206 has 4 divisors (see below), whose sum is σ = 31832283337812. Its totient is φ = 10610761112602.

The previous prime is 21221522225153. The next prime is 21221522225237. The reversal of 21221522225206 is 60252222512212.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5305380556300 + ... + 5305380556303.

It is an arithmetic number, because the mean of its divisors is an integer number (7958070834453).

Almost surely, 2^{21221522225206} is an apocalyptic number.

21221522225206 is a deficient number, since it is larger than the sum of its proper divisors (10610761112606).

21221522225206 is a wasteful number, since it uses less digits than its factorization.

21221522225206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10610761112605.

The product of its (nonzero) digits is 38400, while the sum is 34.

Adding to 21221522225206 its reverse (60252222512212), we get a palindrome (81473744737418).

The spelling of 21221522225206 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-two million, two hundred twenty-five thousand, two hundred six".