1221989983 has 2 divisors, whose sum is σ = 1221989984. Its totient is φ = 1221989982.

The previous prime is 1221989981. The next prime is 1221989987. The reversal of 1221989983 is 3899891221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221989983 - 2¹ = 1221989981 is a prime.

Together with 1221989981, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1221989983.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221989981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610994991 + 610994992.

It is an arithmetic number, because the mean of its divisors is an integer number (610994992).

Almost surely, 2^1221989983 is an apocalyptic number.

1221989983 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221989983 is an equidigital number, since it uses as much as digits as its factorization.

1221989983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 52.

The square root of 1221989983 is about 34956.9733100565. The cubic root of 1221989983 is about 1069.1103861382.

The spelling of 1221989983 in words is "one billion, two hundred twenty-one million, nine hundred eighty-nine thousand, nine hundred eighty-three".