1221230239 has 4 divisors (see below), whose sum is σ = 1239457624. Its totient is φ = 1203002856.

The previous prime is 1221230221. The next prime is 1221230273. The reversal of 1221230239 is 9320321221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9320321221 = 821 ⋅11352401.

It is a cyclic number.

It is not a de Polignac number, because 1221230239 - 2⁹ = 1221229727 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 (1221230299) 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, 9113592 + ... + 9113725.

It is an arithmetic number, because the mean of its divisors is an integer number (309864406).

Almost surely, 2^1221230239 is an apocalyptic number.

1221230239 is a deficient number, since it is larger than the sum of its proper divisors (18227385).

1221230239 is an equidigital number, since it uses as much as digits as its factorization.

1221230239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18227384.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 1221230239 is about 34946.1047757830. The cubic root of 1221230239 is about 1068.8887753222. Note that the first 3 decimals are identical.

The spelling of 1221230239 in words is "one billion, two hundred twenty-one million, two hundred thirty thousand, two hundred thirty-nine".