21405471070071 has 16 divisors (see below), whose sum is σ = 32966714803968. Its totient is φ = 12209894371200.

The previous prime is 21405471070033. The next prime is 21405471070163. The reversal of 21405471070071 is 17007017450412.

It is not a de Polignac number, because 21405471070071 - 2²¹ = 21405468972919 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21405471070171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19077959395 + ... + 19077960516.

It is an arithmetic number, because the mean of its divisors is an integer number (2060419675248).

Almost surely, 2^{21405471070071} is an apocalyptic number.

21405471070071 is a deficient number, since it is larger than the sum of its proper divisors (11561243733897).

21405471070071 is a wasteful number, since it uses less digits than its factorization.

21405471070071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38155919942.

The product of its (nonzero) digits is 54880, while the sum is 39.

The spelling of 21405471070071 in words is "twenty-one trillion, four hundred five billion, four hundred seventy-one million, seventy thousand, seventy-one".