21729725411 has 4 divisors (see below), whose sum is σ = 21929080800. Its totient is φ = 21530370024.

The previous prime is 21729725291. The next prime is 21729725447. The reversal of 21729725411 is 11452792712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21729725411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21729725011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99677531 + ... + 99677748.

It is an arithmetic number, because the mean of its divisors is an integer number (5482270200).

Almost surely, 2^21729725411 is an apocalyptic number.

21729725411 is a deficient number, since it is larger than the sum of its proper divisors (199355389).

21729725411 is a wasteful number, since it uses less digits than its factorization.

21729725411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199355388.

The product of its digits is 70560, while the sum is 41.

The spelling of 21729725411 in words is "twenty-one billion, seven hundred twenty-nine million, seven hundred twenty-five thousand, four hundred eleven".