21025203231 has 8 divisors (see below), whose sum is σ = 28076146560. Its totient is φ = 13995531032.

The previous prime is 21025203223. The next prime is 21025203247. The reversal of 21025203231 is 13230252012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21025203231 - 2³ = 21025203223 is a prime.

It is a super-2 number, since 2×21025203231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21025203198 and 21025203207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21025203131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5315475 + ... + 5319428.

It is an arithmetic number, because the mean of its divisors is an integer number (3509518320).

Almost surely, 2^21025203231 is an apocalyptic number.

21025203231 is a deficient number, since it is larger than the sum of its proper divisors (7050943329).

21025203231 is a wasteful number, since it uses less digits than its factorization.

21025203231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10635565.

The product of its (nonzero) digits is 720, while the sum is 21.

Adding to 21025203231 its reverse (13230252012), we get a palindrome (34255455243).

The spelling of 21025203231 in words is "twenty-one billion, twenty-five million, two hundred three thousand, two hundred thirty-one".