1221405013987 has 2 divisors, whose sum is σ = 1221405013988. Its totient is φ = 1221405013986.

The previous prime is 1221405013979. The next prime is 1221405014057. The reversal of 1221405013987 is 7893105041221.

It is a weak prime.

It is an emirp because it is prime and its reverse (7893105041221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221405013987 - 2³ = 1221405013979 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221402013987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610702506993 + 610702506994.

It is an arithmetic number, because the mean of its divisors is an integer number (610702506994).

Almost surely, 2^{1221405013987} is an apocalyptic number.

1221405013987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221405013987 is an equidigital number, since it uses as much as digits as its factorization.

1221405013987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 1221405013987 in words is "one trillion, two hundred twenty-one billion, four hundred five million, thirteen thousand, nine hundred eighty-seven".