21082777361 has 8 divisors (see below), whose sum is σ = 21477911784. Its totient is φ = 20689240320.

The previous prime is 21082777351. The next prime is 21082777369. The reversal of 21082777361 is 16377728012.

It can be written as a sum of positive squares in 4 ways, for example, as 4780339600 + 16302437761 = 69140^2 + 127681^2 .

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 21082777361 - 2²⁶ = 21015668497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21082777369) 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, 372686 + ... + 425511.

It is an arithmetic number, because the mean of its divisors is an integer number (2684738973).

Almost surely, 2^21082777361 is an apocalyptic number.

It is an amenable number.

21082777361 is a deficient number, since it is larger than the sum of its proper divisors (395134423).

21082777361 is an equidigital number, since it uses as much as digits as its factorization.

21082777361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798691.

The product of its (nonzero) digits is 197568, while the sum is 44.

The spelling of 21082777361 in words is "twenty-one billion, eighty-two million, seven hundred seventy-seven thousand, three hundred sixty-one".