2021011121989 has 2 divisors, whose sum is σ = 2021011121990. Its totient is φ = 2021011121988.

The previous prime is 2021011121953. The next prime is 2021011122059. The reversal of 2021011121989 is 9891211101202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1974854037025 + 46157084964 = 1405295^2 + 214842^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021011121989 - 2⁷ = 2021011121861 is a prime.

It is a super-2 number, since 2×2021011121989² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021011122989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010505560994 + 1010505560995.

It is an arithmetic number, because the mean of its divisors is an integer number (1010505560995).

Almost surely, 2^{2021011121989} is an apocalyptic number.

It is an amenable number.

2021011121989 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021011121989 is an equidigital number, since it uses as much as digits as its factorization.

2021011121989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 37.

The spelling of 2021011121989 in words is "two trillion, twenty-one billion, eleven million, one hundred twenty-one thousand, nine hundred eighty-nine".