1001021000121 has 12 divisors (see below), whose sum is σ = 1449525011220. Its totient is φ = 665683123200.

The previous prime is 1001021000039. The next prime is 1001021000129. The reversal of 1001021000121 is 1210001201001.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 960378440121 + 40642560000 = 979989^2 + 201600^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1001021000121 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 (1001021000129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 138680376 + ... + 138687593.

It is an arithmetic number, because the mean of its divisors is an integer number (120793750935).

Almost surely, 2^{1001021000121} is an apocalyptic number.

It is an amenable number.

1001021000121 is a deficient number, since it is larger than the sum of its proper divisors (448504011099).

1001021000121 is a wasteful number, since it uses less digits than its factorization.

1001021000121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277368376 (or 277368373 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1001021000121 its reverse (1210001201001), we get a palindrome (2211022201122).

The spelling of 1001021000121 in words is "one trillion, one billion, twenty-one million, one hundred twenty-one", and thus it is an aban number.