21585808403 has 2 divisors, whose sum is σ = 21585808404. Its totient is φ = 21585808402.

The previous prime is 21585808331. The next prime is 21585808411. The reversal of 21585808403 is 30480858512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21585808403 - 2¹⁰ = 21585807379 is a prime.

It is a super-2 number, since 2×21585808403² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21585808483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10792904201 + 10792904202.

It is an arithmetic number, because the mean of its divisors is an integer number (10792904202).

Almost surely, 2^21585808403 is an apocalyptic number.

21585808403 is a deficient number, since it is larger than the sum of its proper divisors (1).

21585808403 is an equidigital number, since it uses as much as digits as its factorization.

21585808403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 307200, while the sum is 44.

The spelling of 21585808403 in words is "twenty-one billion, five hundred eighty-five million, eight hundred eight thousand, four hundred three".