21298111540987 has 2 divisors, whose sum is σ = 21298111540988. Its totient is φ = 21298111540986.

The previous prime is 21298111540967. The next prime is 21298111540997. The reversal of 21298111540987 is 78904511189212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21298111540987 - 2²³ = 21298103152379 is a prime.

It is not a weakly prime, because it can be changed into another prime (21298111540957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10649055770493 + 10649055770494.

It is an arithmetic number, because the mean of its divisors is an integer number (10649055770494).

Almost surely, 2^{21298111540987} is an apocalyptic number.

21298111540987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21298111540987 is an equidigital number, since it uses as much as digits as its factorization.

21298111540987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2903040, while the sum is 58.

The spelling of 21298111540987 in words is "twenty-one trillion, two hundred ninety-eight billion, one hundred eleven million, five hundred forty thousand, nine hundred eighty-seven".