21434232161 has 2 divisors, whose sum is σ = 21434232162. Its totient is φ = 21434232160.

The previous prime is 21434232121. The next prime is 21434232167. The reversal of 21434232161 is 16123243412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13416820561 + 8017411600 = 115831^2 + 89540^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21434232161 is a prime.

It is not a weakly prime, because it can be changed into another prime (21434232167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10717116080 + 10717116081.

It is an arithmetic number, because the mean of its divisors is an integer number (10717116081).

Almost surely, 2^21434232161 is an apocalyptic number.

It is an amenable number.

21434232161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21434232161 is an equidigital number, since it uses as much as digits as its factorization.

21434232161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 29.

Adding to 21434232161 its reverse (16123243412), we get a palindrome (37557475573).

The spelling of 21434232161 in words is "twenty-one billion, four hundred thirty-four million, two hundred thirty-two thousand, one hundred sixty-one".