21500520221353 has 16 divisors (see below), whose sum is σ = 23329295009856. Its totient is φ = 19735814891520.

The previous prime is 21500520221287. The next prime is 21500520221357. The reversal of 21500520221353 is 35312202500512.

It is a cyclic number.

It is not a de Polignac number, because 21500520221353 - 2⁹ = 21500520220841 is a prime.

It is a super-2 number, since 2×21500520221353² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21500520221357) 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, 21359803 + ... + 22343728.

It is an arithmetic number, because the mean of its divisors is an integer number (1458080938116).

Almost surely, 2^{21500520221353} is an apocalyptic number.

It is an amenable number.

21500520221353 is a deficient number, since it is larger than the sum of its proper divisors (1828774788503).

21500520221353 is a wasteful number, since it uses less digits than its factorization.

21500520221353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43704264.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 21500520221353 its reverse (35312202500512), we get a palindrome (56812722721865).

The spelling of 21500520221353 in words is "twenty-one trillion, five hundred billion, five hundred twenty million, two hundred twenty-one thousand, three hundred fifty-three".