21888670555205 has 8 divisors (see below), whose sum is σ = 26275663197432. Its totient is φ = 17504764090048.

The previous prime is 21888670555189. The next prime is 21888670555211. The reversal of 21888670555205 is 50255507688812.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 142135786081 + 21746534769124 = 377009^2 + 4663318^2 .

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 21888670555205 - 2⁴ = 21888670555189 is a prime.

It is a super-2 number, since 2×21888670555205² (a number of 27 digits) contains 22 as substring.

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, 771528662 + ... + 771557031.

It is an arithmetic number, because the mean of its divisors is an integer number (3284457899679).

Almost surely, 2^{21888670555205} is an apocalyptic number.

It is an amenable number.

21888670555205 is a deficient number, since it is larger than the sum of its proper divisors (4386992642227).

21888670555205 is a wasteful number, since it uses less digits than its factorization.

21888670555205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543088535.

The product of its (nonzero) digits is 53760000, while the sum is 62.

The spelling of 21888670555205 in words is "twenty-one trillion, eight hundred eighty-eight billion, six hundred seventy million, five hundred fifty-five thousand, two hundred five".