21206322125 has 32 divisors (see below), whose sum is σ = 26950060800. Its totient is φ = 16655496000.

The previous prime is 21206322119. The next prime is 21206322127. The reversal of 21206322125 is 52122360212.

It is not a de Polignac number, because 21206322125 - 2²⁰ = 21205273549 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21206322094 and 21206322103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21206322127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4565054 + ... + 4569696.

It is an arithmetic number, because the mean of its divisors is an integer number (842189400).

Almost surely, 2^21206322125 is an apocalyptic number.

21206322125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21206322125 is a deficient number, since it is larger than the sum of its proper divisors (5743738675).

21206322125 is an equidigital number, since it uses as much as digits as its factorization.

21206322125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5318 (or 5308 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 21206322125 its reverse (52122360212), we get a palindrome (73328682337).

The spelling of 21206322125 in words is "twenty-one billion, two hundred six million, three hundred twenty-two thousand, one hundred twenty-five".