20001223961 has 2 divisors, whose sum is σ = 20001223962. Its totient is φ = 20001223960.

The previous prime is 20001223927. The next prime is 20001223993. The reversal of 20001223961 is 16932210002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14048175625 + 5953048336 = 118525^2 + 77156^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001223961 - 2⁶ = 20001223897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20001223961.

It is not a weakly prime, because it can be changed into another prime (20001220961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000611980 + 10000611981.

It is an arithmetic number, because the mean of its divisors is an integer number (10000611981).

Almost surely, 2^20001223961 is an apocalyptic number.

It is an amenable number.

20001223961 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001223961 is an equidigital number, since it uses as much as digits as its factorization.

20001223961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 26.

Adding to 20001223961 its reverse (16932210002), we get a palindrome (36933433963).

The spelling of 20001223961 in words is "twenty billion, one million, two hundred twenty-three thousand, nine hundred sixty-one".