20011221943 has 2 divisors, whose sum is σ = 20011221944. Its totient is φ = 20011221942.

The previous prime is 20011221887. The next prime is 20011221949. The reversal of 20011221943 is 34912211002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20011221943 - 2²⁹ = 19474351031 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011221949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005610971 + 10005610972.

It is an arithmetic number, because the mean of its divisors is an integer number (10005610972).

Almost surely, 2^20011221943 is an apocalyptic number.

20011221943 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011221943 is an equidigital number, since it uses as much as digits as its factorization.

20011221943 is an evil number, because the sum of its binary digits is even.

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

Adding to 20011221943 its reverse (34912211002), we get a palindrome (54923432945).

The spelling of 20011221943 in words is "twenty billion, eleven million, two hundred twenty-one thousand, nine hundred forty-three".