1221401239 has 2 divisors, whose sum is σ = 1221401240. Its totient is φ = 1221401238.

The previous prime is 1221401221. The next prime is 1221401243. The reversal of 1221401239 is 9321041221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221401239 - 2⁹ = 1221400727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221401219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610700619 + 610700620.

It is an arithmetic number, because the mean of its divisors is an integer number (610700620).

Almost surely, 2^1221401239 is an apocalyptic number.

1221401239 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221401239 is an equidigital number, since it uses as much as digits as its factorization.

1221401239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1221401239 is about 34948.5513147541. The cubic root of 1221401239 is about 1068.9386625709.

The spelling of 1221401239 in words is "one billion, two hundred twenty-one million, four hundred one thousand, two hundred thirty-nine".