21903962809 has 2 divisors, whose sum is σ = 21903962810. Its totient is φ = 21903962808.

The previous prime is 21903962747. The next prime is 21903962863. The reversal of 21903962809 is 90826930912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20677002025 + 1226960784 = 143795^2 + 35028^2 .

It is a cyclic number.

It is not a de Polignac number, because 21903962809 - 2¹³ = 21903954617 is a prime.

It is not a weakly prime, because it can be changed into another prime (21903960809) 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, 10951981404 + 10951981405.

It is an arithmetic number, because the mean of its divisors is an integer number (10951981405).

Almost surely, 2^21903962809 is an apocalyptic number.

It is an amenable number.

21903962809 is a deficient number, since it is larger than the sum of its proper divisors (1).

21903962809 is an equidigital number, since it uses as much as digits as its factorization.

21903962809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 49.

The spelling of 21903962809 in words is "twenty-one billion, nine hundred three million, nine hundred sixty-two thousand, eight hundred nine".