31020121021987 has 2 divisors, whose sum is σ = 31020121021988. Its totient is φ = 31020121021986.

The previous prime is 31020121021979. The next prime is 31020121022003. The reversal of 31020121021987 is 78912012102013.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (78912012102013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31020121021987 - 2³ = 31020121021979 is a prime.

It is not a weakly prime, because it can be changed into another prime (31020121021927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15510060510993 + 15510060510994.

It is an arithmetic number, because the mean of its divisors is an integer number (15510060510994).

Almost surely, 2^{31020121021987} is an apocalyptic number.

31020121021987 is a deficient number, since it is larger than the sum of its proper divisors (1).

31020121021987 is an equidigital number, since it uses as much as digits as its factorization.

31020121021987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 37.

The spelling of 31020121021987 in words is "thirty-one trillion, twenty billion, one hundred twenty-one million, twenty-one thousand, nine hundred eighty-seven".