1020120100021 has 32 divisors (see below), whose sum is σ = 1189995432192. Its totient is φ = 865291215360.

The previous prime is 1020120100003. The next prime is 1020120100057. The reversal of 1020120100021 is 1200010210201.

It is not a de Polignac number, because 1020120100021 - 2⁷ = 1020120099893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020120099980 and 1020120100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020120100621) 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 31 ways as a sum of consecutive naturals, for example, 2099881 + ... + 2539633.

It is an arithmetic number, because the mean of its divisors is an integer number (37187357256).

Almost surely, 2^{1020120100021} is an apocalyptic number.

1020120100021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1020120100021 is a deficient number, since it is larger than the sum of its proper divisors (169875332171).

1020120100021 is a wasteful number, since it uses less digits than its factorization.

1020120100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440013.

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

Adding to 1020120100021 its reverse (1200010210201), we get a palindrome (2220130310222).

The spelling of 1020120100021 in words is "one trillion, twenty billion, one hundred twenty million, one hundred thousand, twenty-one".