21305543570 has 32 divisors (see below), whose sum is σ = 38804618160. Its totient is φ = 8421304320.

The previous prime is 21305543561. The next prime is 21305543599. The reversal of 21305543570 is 7534550312.

It can be written as a sum of positive squares in 8 ways, for example, as 2668652281 + 18636891289 = 51659^2 + 136517^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21305543570.

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 15 ways as a sum of consecutive naturals, for example, 1660580 + ... + 1673360.

Almost surely, 2^21305543570 is an apocalyptic number.

21305543570 is a deficient number, since it is larger than the sum of its proper divisors (17499074590).

21305543570 is a wasteful number, since it uses less digits than its factorization.

21305543570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14750.

The product of its (nonzero) digits is 63000, while the sum is 35.

The spelling of 21305543570 in words is "twenty-one billion, three hundred five million, five hundred forty-three thousand, five hundred seventy".