1231405125 has 16 divisors (see below), whose sum is σ = 2049058752. Its totient is φ = 656749200.

The previous prime is 1231405121. The next prime is 1231405141. The reversal of 1231405125 is 5215041321.

It is a happy number.

It is not a de Polignac number, because 1231405125 - 2² = 1231405121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1231405095 and 1231405104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231405121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1641499 + ... + 1642248.

It is an arithmetic number, because the mean of its divisors is an integer number (128066172).

Almost surely, 2^1231405125 is an apocalyptic number.

1231405125 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231405125 is a deficient number, since it is larger than the sum of its proper divisors (817653627).

1231405125 is an equidigital number, since it uses as much as digits as its factorization.

1231405125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3283765 (or 3283755 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 1231405125 is about 35091.3824891525. The cubic root of 1231405125 is about 1071.8491114227.

Adding to 1231405125 its reverse (5215041321), we get a palindrome (6446446446).

The spelling of 1231405125 in words is "one billion, two hundred thirty-one million, four hundred five thousand, one hundred twenty-five".