1231391648 has 12 divisors (see below), whose sum is σ = 2424302370. Its totient is φ = 615695808.

The previous prime is 1231391647. The next prime is 1231391717. The reversal of 1231391648 is 8461931321.

It can be written as a sum of positive squares in only one way, i.e., 1092434704 + 138956944 = 33052^2 + 11788^2 .

It is not an unprimeable number, because it can be changed into a prime (1231391647) by changing a digit.

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 as a sum of consecutive naturals, namely, 19240463 + ... + 19240526.

Almost surely, 2^1231391648 is an apocalyptic number.

It is an amenable number.

1231391648 is a deficient number, since it is larger than the sum of its proper divisors (1192910722).

1231391648 is an equidigital number, since it uses as much as digits as its factorization.

1231391648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38480999 (or 38480991 counting only the distinct ones).

The product of its digits is 31104, while the sum is 38.

The square root of 1231391648 is about 35091.1904614249. The cubic root of 1231391648 is about 1071.8452011571.

The spelling of 1231391648 in words is "one billion, two hundred thirty-one million, three hundred ninety-one thousand, six hundred forty-eight".