205421400325 has 24 divisors (see below), whose sum is σ = 256097124360. Its totient is φ = 163450828800.

The previous prime is 205421400319. The next prime is 205421400403. The reversal of 205421400325 is 523004124502.

It can be written as a sum of positive squares in 12 ways, for example, as 80401169601 + 125020230724 = 283551^2 + 353582^2 .

It is not a de Polignac number, because 205421400325 - 2²⁹ = 204884529413 is a prime.

It is a super-2 number, since 2×205421400325² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 205421400293 and 205421400302.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 25019821 + ... + 25028029.

It is an arithmetic number, because the mean of its divisors is an integer number (10670713515).

Almost surely, 2^205421400325 is an apocalyptic number.

205421400325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

205421400325 is a deficient number, since it is larger than the sum of its proper divisors (50675724035).

205421400325 is a wasteful number, since it uses less digits than its factorization.

205421400325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13497 (or 13492 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 28.

Adding to 205421400325 its reverse (523004124502), we get a palindrome (728425524827).

The spelling of 205421400325 in words is "two hundred five billion, four hundred twenty-one million, four hundred thousand, three hundred twenty-five".