21555004535 has 8 divisors (see below), whose sum is σ = 25867894416. Its totient is φ = 17242744320.

The previous prime is 21555004511. The next prime is 21555004543. The reversal of 21555004535 is 53540055512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21555004535 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21555004495 and 21555004504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78506 + ... + 221975.

It is an arithmetic number, because the mean of its divisors is an integer number (3233486802).

Almost surely, 2^21555004535 is an apocalyptic number.

21555004535 is a deficient number, since it is larger than the sum of its proper divisors (4312889881).

21555004535 is a wasteful number, since it uses less digits than its factorization.

21555004535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314833.

The product of its (nonzero) digits is 75000, while the sum is 35.

The spelling of 21555004535 in words is "twenty-one billion, five hundred fifty-five million, four thousand, five hundred thirty-five".