21216404130025 has 24 divisors (see below), whose sum is σ = 28355075686784. Its totient is φ = 15654770683200.

The previous prime is 21216404129959. The next prime is 21216404130041. The reversal of 21216404130025 is 52003140461212.

It is not a de Polignac number, because 21216404130025 - 2⁷ = 21216404129897 is a prime.

It is a Duffinian number.

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 23 ways as a sum of consecutive naturals, for example, 26115459 + ... + 26915608.

Almost surely, 2^{21216404130025} is an apocalyptic number.

21216404130025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21216404130025 is a deficient number, since it is larger than the sum of its proper divisors (7138671556759).

21216404130025 is a wasteful number, since it uses less digits than its factorization.

21216404130025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53032321 (or 53032316 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

Adding to 21216404130025 its reverse (52003140461212), we get a palindrome (73219544591237).

The spelling of 21216404130025 in words is "twenty-one trillion, two hundred sixteen billion, four hundred four million, one hundred thirty thousand, twenty-five".