21677829842549 has 8 divisors (see below), whose sum is σ = 22434619460760. Its totient is φ = 20921658774016.

The previous prime is 21677829842531. The next prime is 21677829842597. The reversal of 21677829842549 is 94524892877612.

It can be written as a sum of positive squares in 4 ways, for example, as 16334473977649 + 5343355864900 = 4041593^2 + 2311570^2 .

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 21677829842549 - 2⁸ = 21677829842293 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21677829842749) 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, 154566104 + ... + 154706289.

It is an arithmetic number, because the mean of its divisors is an integer number (2804327432595).

Almost surely, 2^{21677829842549} is an apocalyptic number.

21677829842549 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21677829842549 is a deficient number, since it is larger than the sum of its proper divisors (756789618211).

21677829842549 is a wasteful number, since it uses less digits than its factorization.

21677829842549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309274839.

The product of its digits is 975421440, while the sum is 74.

The spelling of 21677829842549 in words is "twenty-one trillion, six hundred seventy-seven billion, eight hundred twenty-nine million, eight hundred forty-two thousand, five hundred forty-nine".