1231115642 has 4 divisors (see below), whose sum is σ = 1846673466. Its totient is φ = 615557820.

The previous prime is 1231115609. The next prime is 1231115663. The reversal of 1231115642 is 2465111321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2465111321 = 61 ⋅40411661.

It can be written as a sum of positive squares in only one way, i.e., 1081028641 + 150087001 = 32879^2 + 12251^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 307778909 + ... + 307778912.

Almost surely, 2^1231115642 is an apocalyptic number.

1231115642 is a deficient number, since it is larger than the sum of its proper divisors (615557824).

1231115642 is an equidigital number, since it uses as much as digits as its factorization.

1231115642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615557823.

The product of its digits is 1440, while the sum is 26.

The square root of 1231115642 is about 35087.2575445845. The cubic root of 1231115642 is about 1071.7651135011.

Adding to 1231115642 its reverse (2465111321), we get a palindrome (3696226963).

The spelling of 1231115642 in words is "one billion, two hundred thirty-one million, one hundred fifteen thousand, six hundred forty-two".