1002000020121 has 24 divisors (see below), whose sum is σ = 1510608435336. Its totient is φ = 639410952960.

The previous prime is 1002000019997. The next prime is 1002000020123. The reversal of 1002000020121 is 1210200002001.

It can be written as a sum of positive squares in 4 ways, for example, as 921729600 + 1001078290521 = 30360^2 + 1000539^2 .

It is not a de Polignac number, because 1002000020121 - 2³⁵ = 967640281753 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (1002000020123) 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 23 ways as a sum of consecutive naturals, for example, 25597870 + ... + 25636983.

It is an arithmetic number, because the mean of its divisors is an integer number (62942018139).

Almost surely, 2^{1002000020121} is an apocalyptic number.

It is an amenable number.

1002000020121 is a deficient number, since it is larger than the sum of its proper divisors (508608415215).

1002000020121 is a wasteful number, since it uses less digits than its factorization.

1002000020121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51234953 (or 51234950 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1002000020121 its reverse (1210200002001), we get a palindrome (2212200022122).

The spelling of 1002000020121 in words is "one trillion, two billion, twenty thousand, one hundred twenty-one".