21245135345554 has 8 divisors (see below), whose sum is σ = 31867785342000. Its totient is φ = 10622540231556.

The previous prime is 21245135345543. The next prime is 21245135345627. The reversal of 21245135345554 is 45554353154212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21245135345498 and 21245135345507.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12738804 + ... + 14309695.

It is an arithmetic number, because the mean of its divisors is an integer number (3983473167750).

Almost surely, 2^{21245135345554} is an apocalyptic number.

21245135345554 is a deficient number, since it is larger than the sum of its proper divisors (10622649996446).

21245135345554 is a wasteful number, since it uses less digits than its factorization.

21245135345554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27441224.

The product of its digits is 7200000, while the sum is 49.

Adding to 21245135345554 its reverse (45554353154212), we get a palindrome (66799488499766).

The spelling of 21245135345554 in words is "twenty-one trillion, two hundred forty-five billion, one hundred thirty-five million, three hundred forty-five thousand, five hundred fifty-four".