21220201131988 has 24 divisors (see below), whose sum is σ = 38041711361640. Its totient is φ = 10351149166080.

The previous prime is 21220201131971. The next prime is 21220201131989. The reversal of 21220201131988 is 88913110202212.

It can be written as a sum of positive squares in 4 ways, for example, as 5999060692804 + 15221140439184 = 2449298^2 + 3901428^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21220201131988.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220201131989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9368698 + ... + 11411086.

It is an arithmetic number, because the mean of its divisors is an integer number (1585071306735).

Almost surely, 2^{21220201131988} is an apocalyptic number.

It is an amenable number.

21220201131988 is a deficient number, since it is larger than the sum of its proper divisors (16821510229652).

21220201131988 is a wasteful number, since it uses less digits than its factorization.

21220201131988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2105787 (or 2105785 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 40.

The spelling of 21220201131988 in words is "twenty-one trillion, two hundred twenty billion, two hundred one million, one hundred thirty-one thousand, nine hundred eighty-eight".