21564542703 has 16 divisors (see below), whose sum is σ = 31370472576. Its totient is φ = 13067809440.

The previous prime is 21564542627. The next prime is 21564542711. The reversal of 21564542703 is 30724546512.

It is not a de Polignac number, because 21564542703 - 2¹⁸ = 21564280559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21564542743) 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 15 ways as a sum of consecutive naturals, for example, 266500 + ... + 337862.

It is an arithmetic number, because the mean of its divisors is an integer number (1960654536).

Almost surely, 2^21564542703 is an apocalyptic number.

21564542703 is a deficient number, since it is larger than the sum of its proper divisors (9805929873).

21564542703 is a wasteful number, since it uses less digits than its factorization.

21564542703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80534.

The product of its (nonzero) digits is 201600, while the sum is 39.

The spelling of 21564542703 in words is "twenty-one billion, five hundred sixty-four million, five hundred forty-two thousand, seven hundred three".