21545554105233 has 16 divisors (see below), whose sum is σ = 31919671935360. Its totient is φ = 14363553102768.

The previous prime is 21545554105123. The next prime is 21545554105249. The reversal of 21545554105233 is 33250145554512.

21545554105233 is a `hidden beast` number, since 2 + 1 + 5 + 4 + 5 + 554 + 10 + 52 + 33 = 666.

It is not a de Polignac number, because 21545554105233 - 2¹⁰ = 21545554104209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21545554103233) 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, 1485510 + ... + 6730367.

It is an arithmetic number, because the mean of its divisors is an integer number (1994979495960).

Almost surely, 2^{21545554105233} is an apocalyptic number.

It is an amenable number.

21545554105233 is a deficient number, since it is larger than the sum of its proper divisors (10374117830127).

21545554105233 is an equidigital number, since it uses as much as digits as its factorization.

21545554105233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8313013 (or 8313007 counting only the distinct ones).

The product of its (nonzero) digits is 1800000, while the sum is 45.

Adding to 21545554105233 its reverse (33250145554512), we get a palindrome (54795699659745).

The spelling of 21545554105233 in words is "twenty-one trillion, five hundred forty-five billion, five hundred fifty-four million, one hundred five thousand, two hundred thirty-three".