1221773387 has 2 divisors, whose sum is σ = 1221773388. Its totient is φ = 1221773386.

The previous prime is 1221773381. The next prime is 1221773407. The reversal of 1221773387 is 7833771221.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (7833771221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221773387 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221773381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610886693 + 610886694.

It is an arithmetic number, because the mean of its divisors is an integer number (610886694).

Almost surely, 2^1221773387 is an apocalyptic number.

1221773387 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221773387 is an equidigital number, since it uses as much as digits as its factorization.

1221773387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 98784, while the sum is 41.

The square root of 1221773387 is about 34953.8751356699. The cubic root of 1221773387 is about 1069.0472163034.

The spelling of 1221773387 in words is "one billion, two hundred twenty-one million, seven hundred seventy-three thousand, three hundred eighty-seven".