21003675405 has 8 divisors (see below), whose sum is σ = 33605880672. Its totient is φ = 11201960208.

The previous prime is 21003675397. The next prime is 21003675449. The reversal of 21003675405 is 50457630012.

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

It is not a de Polignac number, because 21003675405 - 2³ = 21003675397 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 700122499 + ... + 700122528.

It is an arithmetic number, because the mean of its divisors is an integer number (4200735084).

Almost surely, 2^21003675405 is an apocalyptic number.

It is an amenable number.

21003675405 is a deficient number, since it is larger than the sum of its proper divisors (12602205267).

21003675405 is a wasteful number, since it uses less digits than its factorization.

21003675405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400245035.

The product of its (nonzero) digits is 25200, while the sum is 33.

The spelling of 21003675405 in words is "twenty-one billion, three million, six hundred seventy-five thousand, four hundred five".