21260709547 has 32 divisors (see below), whose sum is σ = 27920908800. Its totient is φ = 15684192000.

The previous prime is 21260709511. The next prime is 21260709559. The reversal of 21260709547 is 74590706212.

It is a cyclic number.

It is not a de Polignac number, because 21260709547 - 2¹⁵ = 21260676779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21260709047) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2630829 + ... + 2638897.

It is an arithmetic number, because the mean of its divisors is an integer number (872528400).

Almost surely, 2^21260709547 is an apocalyptic number.

21260709547 is a deficient number, since it is larger than the sum of its proper divisors (6660199253).

21260709547 is a wasteful number, since it uses less digits than its factorization.

21260709547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9907.

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 21260709547 in words is "twenty-one billion, two hundred sixty million, seven hundred nine thousand, five hundred forty-seven".