20001523221 has 12 divisors (see below), whose sum is σ = 28918644300. Its totient is φ = 13321631040.

The previous prime is 20001523219. The next prime is 20001523249. The reversal of 20001523221 is 12232510002.

It can be written as a sum of positive squares in 2 ways, for example, as 10821200625 + 9180322596 = 104025^2 + 95814^2 .

It is not a de Polignac number, because 20001523221 - 2¹ = 20001523219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001523194 and 20001523203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001523291) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1049850 + ... + 1068731.

It is an arithmetic number, because the mean of its divisors is an integer number (2409887025).

Almost surely, 2^20001523221 is an apocalyptic number.

It is an amenable number.

20001523221 is a deficient number, since it is larger than the sum of its proper divisors (8917121079).

20001523221 is a wasteful number, since it uses less digits than its factorization.

20001523221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2119636 (or 2119633 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The spelling of 20001523221 in words is "twenty billion, one million, five hundred twenty-three thousand, two hundred twenty-one".