1021121000021 has 8 divisors (see below), whose sum is σ = 1030589718840. Its totient is φ = 1011654111168.

The previous prime is 1021120999993. The next prime is 1021121000057. The reversal of 1021121000021 is 1200001211201.

It can be written as a sum of positive squares in 4 ways, for example, as 10772364100 + 1010348635921 = 103790^2 + 1005161^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1021121000021 - 2¹⁸ = 1021120737877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021120999966 and 1021121000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021121000071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 676655 + ... + 1581171.

It is an arithmetic number, because the mean of its divisors is an integer number (128823714855).

Almost surely, 2^{1021121000021} is an apocalyptic number.

It is an amenable number.

1021121000021 is a deficient number, since it is larger than the sum of its proper divisors (9468718819).

1021121000021 is a wasteful number, since it uses less digits than its factorization.

1021121000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914983.

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

Adding to 1021121000021 its reverse (1200001211201), we get a palindrome (2221122211222).

The spelling of 1021121000021 in words is "one trillion, twenty-one billion, one hundred twenty-one million, twenty-one", and thus it is an aban number.