2121020021987 has 2 divisors, whose sum is σ = 2121020021988. Its totient is φ = 2121020021986.

The previous prime is 2121020021977. The next prime is 2121020022001. The reversal of 2121020021987 is 7891200201212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121020021987 - 2³⁴ = 2103840152803 is a prime.

It is a super-3 number, since 3×2121020021987³ (a number of 38 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (2121020021947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060510010993 + 1060510010994.

It is an arithmetic number, because the mean of its divisors is an integer number (1060510010994).

Almost surely, 2^{2121020021987} is an apocalyptic number.

2121020021987 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121020021987 is an equidigital number, since it uses as much as digits as its factorization.

2121020021987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 35.

The spelling of 2121020021987 in words is "two trillion, one hundred twenty-one billion, twenty million, twenty-one thousand, nine hundred eighty-seven".