21603868529 has 4 divisors (see below), whose sum is σ = 21699039984. Its totient is φ = 21508697076.

The previous prime is 21603868459. The next prime is 21603868541. The reversal of 21603868529 is 92586830612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21603868529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21603868579) 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 in 3 ways as a sum of consecutive naturals, for example, 47585387 + ... + 47585840.

It is an arithmetic number, because the mean of its divisors is an integer number (5424759996).

Almost surely, 2^21603868529 is an apocalyptic number.

It is an amenable number.

21603868529 is a deficient number, since it is larger than the sum of its proper divisors (95171455).

21603868529 is an equidigital number, since it uses as much as digits as its factorization.

21603868529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95171454.

The product of its (nonzero) digits is 1244160, while the sum is 50.

The spelling of 21603868529 in words is "twenty-one billion, six hundred three million, eight hundred sixty-eight thousand, five hundred twenty-nine".