21163533146225 has 12 divisors (see below), whose sum is σ = 26242911530316. Its totient is φ = 16930742369280.

The previous prime is 21163533146167. The next prime is 21163533146263. The reversal of 21163533146225 is 52264133536112.

It can be written as a sum of positive squares in 6 ways, for example, as 48984312976 + 21114548833249 = 221324^2 + 4595057^2 .

It is not a de Polignac number, because 21163533146225 - 2⁸ = 21163533145969 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3299069 + ... + 7294581.

It is an arithmetic number, because the mean of its divisors is an integer number (2186909294193).

Almost surely, 2^{21163533146225} is an apocalyptic number.

21163533146225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21163533146225 is a deficient number, since it is larger than the sum of its proper divisors (5079378384091).

21163533146225 is a wasteful number, since it uses less digits than its factorization.

21163533146225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4207396 (or 4207391 counting only the distinct ones).

The product of its digits is 777600, while the sum is 44.

The spelling of 21163533146225 in words is "twenty-one trillion, one hundred sixty-three billion, five hundred thirty-three million, one hundred forty-six thousand, two hundred twenty-five".