1231661325 has 24 divisors (see below), whose sum is σ = 2037369600. Its totient is φ = 656556160.

The previous prime is 1231661323. The next prime is 1231661351. The reversal of 1231661325 is 5231661321.

It is not a de Polignac number, because 1231661325 - 2¹ = 1231661323 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1231661292 and 1231661301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231661323) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 249481 + ... + 254369.

It is an arithmetic number, because the mean of its divisors is an integer number (84890400).

Almost surely, 2^1231661325 is an apocalyptic number.

1231661325 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231661325 is a deficient number, since it is larger than the sum of its proper divisors (805708275).

1231661325 is a wasteful number, since it uses less digits than its factorization.

1231661325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8261 (or 8256 counting only the distinct ones).

The product of its digits is 6480, while the sum is 30.

The square root of 1231661325 is about 35095.0327681853. The cubic root of 1231661325 is about 1071.9234407923.

The spelling of 1231661325 in words is "one billion, two hundred thirty-one million, six hundred sixty-one thousand, three hundred twenty-five".