21275437443481 has 8 divisors (see below), whose sum is σ = 22912122894920. Its totient is φ = 19638768183552.

The previous prime is 21275437443479. The next prime is 21275437443517. The reversal of 21275437443481 is 18434473457212.

It can be written as a sum of positive squares in 4 ways, for example, as 834689881 + 21274602753600 = 28891^2 + 4612440^2 .

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 21275437443481 - 2¹ = 21275437443479 is a prime.

It is a super-2 number, since 2×21275437443481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21275437443781) 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, 1247040 + ... + 6641233.

It is an arithmetic number, because the mean of its divisors is an integer number (2864015361865).

Almost surely, 2^{21275437443481} is an apocalyptic number.

It is an amenable number.

21275437443481 is a deficient number, since it is larger than the sum of its proper divisors (1636685451439).

21275437443481 is a wasteful number, since it uses less digits than its factorization.

21275437443481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8095755.

The product of its digits is 18063360, while the sum is 55.

The spelling of 21275437443481 in words is "twenty-one trillion, two hundred seventy-five billion, four hundred thirty-seven million, four hundred forty-three thousand, four hundred eighty-one".