21642103061 has 2 divisors, whose sum is σ = 21642103062. Its totient is φ = 21642103060.

The previous prime is 21642103039. The next prime is 21642103103. The reversal of 21642103061 is 16030124612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15402051025 + 6240052036 = 124105^2 + 78994^2 .

It is a cyclic number.

It is not a de Polignac number, because 21642103061 - 2¹⁰ = 21642102037 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21642103061.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21642103001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10821051530 + 10821051531.

It is an arithmetic number, because the mean of its divisors is an integer number (10821051531).

Almost surely, 2^21642103061 is an apocalyptic number.

It is an amenable number.

21642103061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21642103061 is an equidigital number, since it uses as much as digits as its factorization.

21642103061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 26.

Adding to 21642103061 its reverse (16030124612), we get a palindrome (37672227673).

The spelling of 21642103061 in words is "twenty-one billion, six hundred forty-two million, one hundred three thousand, sixty-one".