1220101100021 has 2 divisors, whose sum is σ = 1220101100022. Its totient is φ = 1220101100020.

The previous prime is 1220101099991. The next prime is 1220101100089. The reversal of 1220101100021 is 1200011010221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1208889255025 + 11211844996 = 1099495^2 + 105886^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220101100021 - 2¹⁴ = 1220101083637 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1220101099975 and 1220101100011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220101100521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610050550010 + 610050550011.

It is an arithmetic number, because the mean of its divisors is an integer number (610050550011).

Almost surely, 2^{1220101100021} is an apocalyptic number.

It is an amenable number.

1220101100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220101100021 is an equidigital number, since it uses as much as digits as its factorization.

1220101100021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1220101100021 its reverse (1200011010221), we get a palindrome (2420112110242).

The spelling of 1220101100021 in words is "one trillion, two hundred twenty billion, one hundred one million, one hundred thousand, twenty-one".