21094840225 has 12 divisors (see below), whose sum is σ = 26161857900. Its totient is φ = 16873126400.

The previous prime is 21094840223. The next prime is 21094840237. The reversal of 21094840225 is 52204849012.

It can be written as a sum of positive squares in 6 ways, for example, as 350775441 + 20744064784 = 18729^2 + 144028^2 .

It is not a de Polignac number, because 21094840225 - 2¹ = 21094840223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21094840223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95805 + ... + 226645.

It is an arithmetic number, because the mean of its divisors is an integer number (2180154825).

Almost surely, 2^21094840225 is an apocalyptic number.

21094840225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21094840225 is a deficient number, since it is larger than the sum of its proper divisors (5067017675).

21094840225 is a wasteful number, since it uses less digits than its factorization.

21094840225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137300 (or 137295 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The spelling of 21094840225 in words is "twenty-one billion, ninety-four million, eight hundred forty thousand, two hundred twenty-five".