1231155225 has 36 divisors (see below), whose sum is σ = 2207687196. Its totient is φ = 655856640.

The previous prime is 1231155209. The next prime is 1231155269. The reversal of 1231155225 is 5225511321.

1231155225 is a `hidden beast` number, since 1 + 23 + 115 + 522 + 5 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 128051856 + 1103103369 = 11316^2 + 33213^2 .

It is not a de Polignac number, because 1231155225 - 2⁴ = 1231155209 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 229777 + ... + 235073.

Almost surely, 2^1231155225 is an apocalyptic number.

1231155225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231155225 is a deficient number, since it is larger than the sum of its proper divisors (976531971).

1231155225 is a wasteful number, since it uses less digits than its factorization.

1231155225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6346 (or 6338 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 1231155225 is about 35087.8216052237. The cubic root of 1231155225 is about 1071.7765998913.

Adding to 1231155225 its reverse (5225511321), we get a palindrome (6456666546).

The spelling of 1231155225 in words is "one billion, two hundred thirty-one million, one hundred fifty-five thousand, two hundred twenty-five".