205401253240 has 32 divisors (see below), whose sum is σ = 462168018000. Its totient is φ = 82157799424.

The previous prime is 205401253201. The next prime is 205401253243. The reversal of 205401253240 is 42352104502.

It is a super-2 number, since 2×205401253240² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 205401253199 and 205401253208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205401253243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1526616 + ... + 1655704.

Almost surely, 2^205401253240 is an apocalyptic number.

205401253240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205401253240 is an abundant number, since it is smaller than the sum of its proper divisors (256766764760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205401253240 is a wasteful number, since it uses less digits than its factorization.

205401253240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168879 (or 168875 counting only the distinct ones).

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

Adding to 205401253240 its reverse (42352104502), we get a palindrome (247753357742).

The spelling of 205401253240 in words is "two hundred five billion, four hundred one million, two hundred fifty-three thousand, two hundred forty".