20555105521 has 16 divisors (see below), whose sum is σ = 22098398400. Its totient is φ = 19060800768.

The previous prime is 20555105509. The next prime is 20555105533. The reversal of 20555105521 is 12550155502.

It is an interprime number because it is at equal distance from previous prime (20555105509) and next prime (20555105533).

It is a cyclic number.

It is not a de Polignac number, because 20555105521 - 2²¹ = 20553008369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20555105561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 221845 + ... + 300541.

It is an arithmetic number, because the mean of its divisors is an integer number (1381149900).

Almost surely, 2^20555105521 is an apocalyptic number.

It is an amenable number.

20555105521 is a deficient number, since it is larger than the sum of its proper divisors (1543292879).

20555105521 is a wasteful number, since it uses less digits than its factorization.

20555105521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79008.

The product of its (nonzero) digits is 12500, while the sum is 31.

The spelling of 20555105521 in words is "twenty billion, five hundred fifty-five million, one hundred five thousand, five hundred twenty-one".