205121235245 has 8 divisors (see below), whose sum is σ = 246156303480. Its totient is φ = 164089774080.

The previous prime is 205121235239. The next prime is 205121235251. The reversal of 205121235245 is 542532121502.

It is an interprime number because it is at equal distance from previous prime (205121235239) and next prime (205121235251).

It can be written as a sum of positive squares in 4 ways, for example, as 48370964356 + 156750270889 = 219934^2 + 395917^2 .

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

It is not a de Polignac number, because 205121235245 - 2¹⁰ = 205121234221 is a prime.

It is a super-2 number, since 2×205121235245² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 775040 + ... + 1005449.

It is an arithmetic number, because the mean of its divisors is an integer number (30769537935).

Almost surely, 2^205121235245 is an apocalyptic number.

It is an amenable number.

205121235245 is a deficient number, since it is larger than the sum of its proper divisors (41035068235).

205121235245 is a wasteful number, since it uses less digits than its factorization.

205121235245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1803535.

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 205121235245 its reverse (542532121502), we get a palindrome (747653356747).

The spelling of 205121235245 in words is "two hundred five billion, one hundred twenty-one million, two hundred thirty-five thousand, two hundred forty-five".