1220306389 has 4 divisors (see below), whose sum is σ = 1220376256. Its totient is φ = 1220236524.

The previous prime is 1220306371. The next prime is 1220306401. The reversal of 1220306389 is 9836030221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1220306389 - 2⁵ = 1220306357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220306489) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17332 + ... + 52354.

It is an arithmetic number, because the mean of its divisors is an integer number (305094064).

Almost surely, 2^1220306389 is an apocalyptic number.

It is an amenable number.

1220306389 is a deficient number, since it is larger than the sum of its proper divisors (69867).

1220306389 is an equidigital number, since it uses as much as digits as its factorization.

1220306389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69866.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 1220306389 is about 34932.8840635868. The cubic root of 1220306389 is about 1068.6191723218.

The spelling of 1220306389 in words is "one billion, two hundred twenty million, three hundred six thousand, three hundred eighty-nine".