1221440239 has 2 divisors, whose sum is σ = 1221440240. Its totient is φ = 1221440238.

The previous prime is 1221440197. The next prime is 1221440257. The reversal of 1221440239 is 9320441221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221440239 - 2⁷ = 1221440111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221447239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610720119 + 610720120.

It is an arithmetic number, because the mean of its divisors is an integer number (610720120).

Almost surely, 2^1221440239 is an apocalyptic number.

1221440239 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221440239 is an equidigital number, since it uses as much as digits as its factorization.

1221440239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1221440239 is about 34949.1092733420. The cubic root of 1221440239 is about 1068.9500397124.

The spelling of 1221440239 in words is "one billion, two hundred twenty-one million, four hundred forty thousand, two hundred thirty-nine".