21307281445 has 8 divisors (see below), whose sum is σ = 25579091736. Its totient is φ = 17038922496.

The previous prime is 21307281419. The next prime is 21307281451. The reversal of 21307281445 is 54418270312.

It can be written as a sum of positive squares in 4 ways, for example, as 11175449796 + 10131831649 = 105714^2 + 100657^2 .

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 21307281445 - 2¹¹ = 21307279397 is a prime.

It is a Duffinian number.

It is a congruent 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, 849232 + ... + 873961.

It is an arithmetic number, because the mean of its divisors is an integer number (3197386467).

Almost surely, 2^21307281445 is an apocalyptic number.

It is an amenable number.

21307281445 is a deficient number, since it is larger than the sum of its proper divisors (4271810291).

21307281445 is a wasteful number, since it uses less digits than its factorization.

21307281445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1725671.

The product of its (nonzero) digits is 53760, while the sum is 37.

The spelling of 21307281445 in words is "twenty-one billion, three hundred seven million, two hundred eighty-one thousand, four hundred forty-five".