21154043705 has 8 divisors (see below), whose sum is σ = 25389559104. Its totient is φ = 16920097200.

The previous prime is 21154043681. The next prime is 21154043719. The reversal of 21154043705 is 50734045112.

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

It is not a de Polignac number, because 21154043705 - 2¹⁰ = 21154042681 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 362351 + ... + 416660.

It is an arithmetic number, because the mean of its divisors is an integer number (3173694888).

Almost surely, 2^21154043705 is an apocalyptic number.

It is an amenable number.

21154043705 is a deficient number, since it is larger than the sum of its proper divisors (4235515399).

21154043705 is an equidigital number, since it uses as much as digits as its factorization.

21154043705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784447.

The product of its (nonzero) digits is 16800, while the sum is 32.

Adding to 21154043705 its reverse (50734045112), we get a palindrome (71888088817).

The spelling of 21154043705 in words is "twenty-one billion, one hundred fifty-four million, forty-three thousand, seven hundred five".