20121210101021 has 2 divisors, whose sum is σ = 20121210101022. Its totient is φ = 20121210101020.

The previous prime is 20121210101017. The next prime is 20121210101033. The reversal of 20121210101021 is 12010101212102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13790928940996 + 6330281160025 = 3713614^2 + 2516005^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121210101021 - 2² = 20121210101017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20121210100987 and 20121210101005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121210101521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060605050510 + 10060605050511.

It is an arithmetic number, because the mean of its divisors is an integer number (10060605050511).

Almost surely, 2^{20121210101021} is an apocalyptic number.

It is an amenable number.

20121210101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121210101021 is an equidigital number, since it uses as much as digits as its factorization.

20121210101021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20121210101021 its reverse (12010101212102), we get a palindrome (32131311313123).

The spelling of 20121210101021 in words is "twenty trillion, one hundred twenty-one billion, two hundred ten million, one hundred one thousand, twenty-one".