21281071418 has 16 divisors (see below), whose sum is σ = 32372865000. Its totient is φ = 10490802432.

The previous prime is 21281071417. The next prime is 21281071423. The reversal of 21281071418 is 81417018212.

It can be written as a sum of positive squares in 4 ways, for example, as 19162034329 + 2119037089 = 138427^2 + 46033^2 .

It is not an unprimeable number, because it can be changed into a prime (21281071411) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109163 + ... + 233406.

Almost surely, 2^21281071418 is an apocalyptic number.

21281071418 is a deficient number, since it is larger than the sum of its proper divisors (11091793582).

21281071418 is a wasteful number, since it uses less digits than its factorization.

21281071418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343009.

The product of its (nonzero) digits is 7168, while the sum is 35.

The spelling of 21281071418 in words is "twenty-one billion, two hundred eighty-one million, seventy-one thousand, four hundred eighteen".