1231522205 has 4 divisors (see below), whose sum is σ = 1477826652. Its totient is φ = 985217760.

The previous prime is 1231522141. The next prime is 1231522217. The reversal of 1231522205 is 5022251321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 756195001 + 475327204 = 27499^2 + 21802^2 .

It is not a de Polignac number, because 1231522205 - 2⁶ = 1231522141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123152216 + ... + 123152225.

It is an arithmetic number, because the mean of its divisors is an integer number (369456663).

Almost surely, 2^1231522205 is an apocalyptic number.

It is an amenable number.

1231522205 is a deficient number, since it is larger than the sum of its proper divisors (246304447).

1231522205 is an equidigital number, since it uses as much as digits as its factorization.

1231522205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246304446.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 1231522205 is about 35093.0506653383. The cubic root of 1231522205 is about 1071.8830802373.

Adding to 1231522205 its reverse (5022251321), we get a palindrome (6253773526).

The spelling of 1231522205 in words is "one billion, two hundred thirty-one million, five hundred twenty-two thousand, two hundred five".