1220001001021 has 6 divisors (see below), whose sum is σ = 1340992835966. Its totient is φ = 1109091819000.

The previous prime is 1220001000989. The next prime is 1220001001027. The reversal of 1220001001021 is 1201001000221.

It can be written as a sum of positive squares in only one way, i.e., 836604744921 + 383396256100 = 914661^2 + 619190^2 .

It is not a de Polignac number, because 1220001001021 - 2⁵ = 1220001000989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220001000989 and 1220001001007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220001001027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5041326330 + ... + 5041326571.

Almost surely, 2^{1220001001021} is an apocalyptic number.

1220001001021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220001001021 is a deficient number, since it is larger than the sum of its proper divisors (120991834945).

1220001001021 is a wasteful number, since it uses less digits than its factorization.

1220001001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10082652923 (or 10082652912 counting only the distinct ones).

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

Adding to 1220001001021 its reverse (1201001000221), we get a palindrome (2421002001242).

The spelling of 1220001001021 in words is "one trillion, two hundred twenty billion, one million, one thousand, twenty-one".