21500551242245 has 32 divisors (see below), whose sum is σ = 25910347545600. Its totient is φ = 17127487770624.

The previous prime is 21500551242229. The next prime is 21500551242251. The reversal of 21500551242245 is 54224215500512.

It is a cyclic number.

It is not a de Polignac number, because 21500551242245 - 2⁴ = 21500551242229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21500551242199 and 21500551242208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4280417804 + ... + 4280422826.

It is an arithmetic number, because the mean of its divisors is an integer number (809698360800).

Almost surely, 2^{21500551242245} is an apocalyptic number.

It is an amenable number.

21500551242245 is a deficient number, since it is larger than the sum of its proper divisors (4409796303355).

21500551242245 is a wasteful number, since it uses less digits than its factorization.

21500551242245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8589.

The product of its (nonzero) digits is 160000, while the sum is 38.

Adding to 21500551242245 its reverse (54224215500512), we get a palindrome (75724766742757).

The spelling of 21500551242245 in words is "twenty-one trillion, five hundred billion, five hundred fifty-one million, two hundred forty-two thousand, two hundred forty-five".