20121000001021 has 2 divisors, whose sum is σ = 20121000001022. Its totient is φ = 20121000001020.

The previous prime is 20121000000973. The next prime is 20121000001061. The reversal of 20121000001021 is 12010000012102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12380975232921 + 7740024768100 = 3518661^2 + 2782090^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121000001021 - 2¹¹ = 20120999998973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20121000000989 and 20121000001007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121000001061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060500000510 + 10060500000511.

It is an arithmetic number, because the mean of its divisors is an integer number (10060500000511).

Almost surely, 2^{20121000001021} is an apocalyptic number.

It is an amenable number.

20121000001021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121000001021 is an equidigital number, since it uses as much as digits as its factorization.

20121000001021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20121000001021 its reverse (12010000012102), we get a palindrome (32131000013123).

The spelling of 20121000001021 in words is "twenty trillion, one hundred twenty-one billion, one thousand, twenty-one".