21621272470206 has 16 divisors (see below), whose sum is σ = 43267642201344. Its totient is φ = 7202907946584.

The previous prime is 21621272470181. The next prime is 21621272470223. The reversal of 21621272470206 is 60207427212612.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1045708006 + ... + 1045728681.

It is an arithmetic number, because the mean of its divisors is an integer number (2704227637584).

Almost surely, 2^{21621272470206} is an apocalyptic number.

21621272470206 is an abundant number, since it is smaller than the sum of its proper divisors (21646369731138).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21621272470206 is a wasteful number, since it uses less digits than its factorization.

21621272470206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091438415.

The product of its (nonzero) digits is 225792, while the sum is 42.

Adding to 21621272470206 its reverse (60207427212612), we get a palindrome (81828699682818).

The spelling of 21621272470206 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred seventy-two million, four hundred seventy thousand, two hundred six".