21436516705 has 8 divisors (see below), whose sum is σ = 25725609000. Its totient is φ = 17148020736.

The previous prime is 21436516697. The next prime is 21436516753. The reversal of 21436516705 is 50761563412.

It can be written as a sum of positive squares in 4 ways, for example, as 8818712464 + 12617804241 = 93908^2 + 112329^2 .

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 21436516705 - 2³ = 21436516697 is a prime.

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, 65760 + ... + 217249.

It is an arithmetic number, because the mean of its divisors is an integer number (3215701125).

Almost surely, 2^21436516705 is an apocalyptic number.

It is an amenable number.

21436516705 is a deficient number, since it is larger than the sum of its proper divisors (4289092295).

21436516705 is a wasteful number, since it uses less digits than its factorization.

21436516705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298163.

The product of its (nonzero) digits is 151200, while the sum is 40.

The spelling of 21436516705 in words is "twenty-one billion, four hundred thirty-six million, five hundred sixteen thousand, seven hundred five".