1221598394 has 4 divisors (see below), whose sum is σ = 1832397594. Its totient is φ = 610799196.

The previous prime is 1221598387. The next prime is 1221598397. The reversal of 1221598394 is 4938951221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 964413025 + 257185369 = 31055^2 + 16037^2 .

It is not an unprimeable number, because it can be changed into a prime (1221598397) 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, 305399597 + ... + 305399600.

Almost surely, 2^1221598394 is an apocalyptic number.

1221598394 is a deficient number, since it is larger than the sum of its proper divisors (610799200).

1221598394 is an equidigital number, since it uses as much as digits as its factorization.

1221598394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610799199.

The product of its digits is 155520, while the sum is 44.

The square root of 1221598394 is about 34951.3718471822. The cubic root of 1221598394 is about 1068.9961744562.

The spelling of 1221598394 in words is "one billion, two hundred twenty-one million, five hundred ninety-eight thousand, three hundred ninety-four".