21563960539 has 8 divisors (see below), whose sum is σ = 24908104368. Its totient is φ = 18450447360.

The previous prime is 21563960503. The next prime is 21563960543. The reversal of 21563960539 is 93506936512.

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

It is a cyclic number.

It is not a de Polignac number, because 21563960539 - 2⁹ = 21563960027 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21563960492 and 21563960501.

It is not an unprimeable number, because it can be changed into a prime (21563960549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57657462 + ... + 57657835.

It is an arithmetic number, because the mean of its divisors is an integer number (3113513046).

Almost surely, 2^21563960539 is an apocalyptic number.

21563960539 is a deficient number, since it is larger than the sum of its proper divisors (3344143829).

21563960539 is a wasteful number, since it uses less digits than its factorization.

21563960539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115315325.

The product of its (nonzero) digits is 1312200, while the sum is 49.

The spelling of 21563960539 in words is "twenty-one billion, five hundred sixty-three million, nine hundred sixty thousand, five hundred thirty-nine".