201020220100021 has 48 divisors (see below), whose sum is σ = 250161237282096. Its totient is φ = 160487030882304.

The previous prime is 201020220099989. The next prime is 201020220100027. The reversal of 201020220100021 is 120001022020102.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 60525070205796 + 140495149894225 = 7779786^2 + 11853065^2 .

It is not a de Polignac number, because 201020220100021 - 2⁵ = 201020220099989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201020220099974 and 201020220100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201020220100027) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1778615905 + ... + 1778728921.

It is an arithmetic number, because the mean of its divisors is an integer number (5211692443377).

Almost surely, 2^{201020220100021} is an apocalyptic number.

It is an amenable number.

201020220100021 is a deficient number, since it is larger than the sum of its proper divisors (49141017182075).

201020220100021 is a wasteful number, since it uses less digits than its factorization.

201020220100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135158 (or 135151 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 201020220100021 its reverse (120001022020102), we get a palindrome (321021242120123).

The spelling of 201020220100021 in words is "two hundred one trillion, twenty billion, two hundred twenty million, one hundred thousand, twenty-one".