20487620221 has 2 divisors, whose sum is σ = 20487620222. Its totient is φ = 20487620220.

The previous prime is 20487620213. The next prime is 20487620437. The reversal of 20487620221 is 12202678402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19936028025 + 551592196 = 141195^2 + 23486^2 .

It is a cyclic number.

It is not a de Polignac number, because 20487620221 - 2³ = 20487620213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20487626221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10243810110 + 10243810111.

It is an arithmetic number, because the mean of its divisors is an integer number (10243810111).

Almost surely, 2^20487620221 is an apocalyptic number.

It is an amenable number.

20487620221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20487620221 is an equidigital number, since it uses as much as digits as its factorization.

20487620221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21504, while the sum is 34.

The spelling of 20487620221 in words is "twenty billion, four hundred eighty-seven million, six hundred twenty thousand, two hundred twenty-one".