1221398 has 4 divisors (see below), whose sum is σ = 1832100. Its totient is φ = 610698.

The previous prime is 1221391. The next prime is 1221421. The reversal of 1221398 is 8931221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8931221 = 13 ⋅687017.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305348 + ... + 305351.

It is an arithmetic number, because the mean of its divisors is an integer number (458025).

2^1221398 is an apocalyptic number.

1221398 is a deficient number, since it is larger than the sum of its proper divisors (610702).

1221398 is an equidigital number, since it uses as much as digits as its factorization.

1221398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610701.

The product of its digits is 864, while the sum is 26.

The square root of 1221398 is about 1105.1687653929. The cubic root of 1221398 is about 106.8937717674.

The spelling of 1221398 in words is "one million, two hundred twenty-one thousand, three hundred ninety-eight".