21461427377065 has 8 divisors (see below), whose sum is σ = 27734767687368. Its totient is φ = 15848438678400.

The previous prime is 21461427377063. The next prime is 21461427377141. The reversal of 21461427377065 is 56077372416412.

It can be written as a sum of positive squares in 4 ways, for example, as 238600010089 + 21222827366976 = 488467^2 + 4606824^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21461427377065 - 2¹ = 21461427377063 is a prime.

It is a super-2 number, since 2×21461427377065² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21461427376997 and 21461427377015.

It is not an unprimeable number, because it can be changed into a prime (21461427377063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165087902836 + ... + 165087902965.

It is an arithmetic number, because the mean of its divisors is an integer number (3466845960921).

Almost surely, 2^{21461427377065} is an apocalyptic number.

It is an amenable number.

21461427377065 is a deficient number, since it is larger than the sum of its proper divisors (6273340310303).

21461427377065 is a wasteful number, since it uses less digits than its factorization.

21461427377065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330175805819.

The product of its (nonzero) digits is 11854080, while the sum is 55.

The spelling of 21461427377065 in words is "twenty-one trillion, four hundred sixty-one billion, four hundred twenty-seven million, three hundred seventy-seven thousand, sixty-five".