20001021090049 has 2 divisors, whose sum is σ = 20001021090050. Its totient is φ = 20001021090048.

The previous prime is 20001021090047. The next prime is 20001021090059. The reversal of 20001021090049 is 94009012010002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15564129619600 + 4436891470449 = 3945140^2 + 2106393^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001021090049 - 2¹ = 20001021090047 is a prime.

Together with 20001021090047, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20001021089999 and 20001021090026.

It is not a weakly prime, because it can be changed into another prime (20001021090047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000510545024 + 10000510545025.

It is an arithmetic number, because the mean of its divisors is an integer number (10000510545025).

Almost surely, 2^{20001021090049} is an apocalyptic number.

It is an amenable number.

20001021090049 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001021090049 is an equidigital number, since it uses as much as digits as its factorization.

20001021090049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 28.

The spelling of 20001021090049 in words is "twenty trillion, one billion, twenty-one million, ninety thousand, forty-nine".