20011221239 has 2 divisors, whose sum is σ = 20011221240. Its totient is φ = 20011221238.

The previous prime is 20011221193. The next prime is 20011221253. The reversal of 20011221239 is 93212211002.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011221239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011221259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005610619 + 10005610620.

It is an arithmetic number, because the mean of its divisors is an integer number (10005610620).

Almost surely, 2^20011221239 is an apocalyptic number.

20011221239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011221239 is an equidigital number, since it uses as much as digits as its factorization.

20011221239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The spelling of 20011221239 in words is "twenty billion, eleven million, two hundred twenty-one thousand, two hundred thirty-nine".