21500034225 has 24 divisors (see below), whose sum is σ = 35699313312. Its totient is φ = 11417462400.

The previous prime is 21500034223. The next prime is 21500034253. The reversal of 21500034225 is 52243000512.

It is not a de Polignac number, because 21500034225 - 2¹ = 21500034223 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21500034195 and 21500034204.

It is not an unprimeable number, because it can be changed into a prime (21500034223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 597691 + ... + 632640.

It is an arithmetic number, because the mean of its divisors is an integer number (1487471388).

Almost surely, 2^21500034225 is an apocalyptic number.

21500034225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21500034225 is a deficient number, since it is larger than the sum of its proper divisors (14199279087).

21500034225 is a wasteful number, since it uses less digits than its factorization.

21500034225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230577 (or 1230572 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

Adding to 21500034225 its reverse (52243000512), we get a palindrome (73743034737).

The spelling of 21500034225 in words is "twenty-one billion, five hundred million, thirty-four thousand, two hundred twenty-five".