1021200109987 has 2 divisors, whose sum is σ = 1021200109988. Its totient is φ = 1021200109986.

The previous prime is 1021200109921. The next prime is 1021200109991. The reversal of 1021200109987 is 7899010021201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1021200109987 - 2⁷ = 1021200109859 is a prime.

It is not a weakly prime, because it can be changed into another prime (1021200109487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510600054993 + 510600054994.

It is an arithmetic number, because the mean of its divisors is an integer number (510600054994).

Almost surely, 2^{1021200109987} is an apocalyptic number.

1021200109987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021200109987 is an equidigital number, since it uses as much as digits as its factorization.

1021200109987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 40.

The spelling of 1021200109987 in words is "one trillion, twenty-one billion, two hundred million, one hundred nine thousand, nine hundred eighty-seven".