1220671987 has 2 divisors, whose sum is σ = 1220671988. Its totient is φ = 1220671986.

The previous prime is 1220671981. The next prime is 1220671999. The reversal of 1220671987 is 7891760221.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220671987 is a prime.

It is not a weakly prime, because it can be changed into another prime (1220671981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610335993 + 610335994.

It is an arithmetic number, because the mean of its divisors is an integer number (610335994).

Almost surely, 2^1220671987 is an apocalyptic number.

1220671987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220671987 is an equidigital number, since it uses as much as digits as its factorization.

1220671987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 1220671987 is about 34938.1165348105. The cubic root of 1220671987 is about 1068.7258794096.

The spelling of 1220671987 in words is "one billion, two hundred twenty million, six hundred seventy-one thousand, nine hundred eighty-seven".