1020111001821 has 6 divisors (see below), whose sum is σ = 1473493669310. Its totient is φ = 680074001208.

The previous prime is 1020111001817. The next prime is 1020111001883. The reversal of 1020111001821 is 1281001110201.

It can be written as a sum of positive squares in only one way, i.e., 666786564900 + 353324436921 = 816570^2 + 594411^2 .

It is not a de Polignac number, because 1020111001821 - 2² = 1020111001817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020111001794 and 1020111001803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020111008821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 56672833426 + ... + 56672833443.

Almost surely, 2^{1020111001821} is an apocalyptic number.

It is an amenable number.

1020111001821 is a deficient number, since it is larger than the sum of its proper divisors (453382667489).

1020111001821 is a wasteful number, since it uses less digits than its factorization.

1020111001821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113345666875 (or 113345666872 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

The spelling of 1020111001821 in words is "one trillion, twenty billion, one hundred eleven million, one thousand, eight hundred twenty-one".