2121000002001 has 6 divisors (see below), whose sum is σ = 3063666669570. Its totient is φ = 1414000001328.

The previous prime is 2121000001997. The next prime is 2121000002003. The reversal of 2121000002001 is 1002000001212.

It can be written as a sum of positive squares in only one way, i.e., 2013859001025 + 107141000976 = 1419105^2 + 327324^2 .

It is not a de Polignac number, because 2121000002001 - 2² = 2121000001997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 235666666889 = 2121000002001 / (2 + 1 + 2 + 1 + 0 + 0 + 0 + 0 + 0 + 2 + 0 + 0 + 1).

It is not an unprimeable number, because it can be changed into a prime (2121000002003) 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, 117833333436 + ... + 117833333453.

It is an arithmetic number, because the mean of its divisors is an integer number (510611111595).

Almost surely, 2^{2121000002001} is an apocalyptic number.

It is an amenable number.

2121000002001 is a deficient number, since it is larger than the sum of its proper divisors (942666667569).

2121000002001 is a wasteful number, since it uses less digits than its factorization.

2121000002001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235666666895 (or 235666666892 counting only the distinct ones).

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

Adding to 2121000002001 its reverse (1002000001212), we get a palindrome (3123000003213).

The spelling of 2121000002001 in words is "two trillion, one hundred twenty-one billion, two thousand, one".