21655614030161 has 8 divisors (see below), whose sum is σ = 22929836842440. Its totient is φ = 20381431569408.

The previous prime is 21655614030157. The next prime is 21655614030179. The reversal of 21655614030161 is 16103041655612.

It can be written as a sum of positive squares in 4 ways, for example, as 2709233700625 + 18946380329536 = 1645975^2 + 4352744^2 .

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 21655614030161 - 2² = 21655614030157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21655614030121) 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, 8979476 + ... + 11132933.

It is an arithmetic number, because the mean of its divisors is an integer number (2866229605305).

Almost surely, 2^{21655614030161} is an apocalyptic number.

It is an amenable number.

21655614030161 is a deficient number, since it is larger than the sum of its proper divisors (1274222812279).

21655614030161 is a wasteful number, since it uses less digits than its factorization.

21655614030161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20175763.

The product of its (nonzero) digits is 129600, while the sum is 41.

Adding to 21655614030161 its reverse (16103041655612), we get a palindrome (37758655685773).

The spelling of 21655614030161 in words is "twenty-one trillion, six hundred fifty-five billion, six hundred fourteen million, thirty thousand, one hundred sixty-one".