12157222642 has 4 divisors (see below), whose sum is σ = 18235833966. Its totient is φ = 6078611320.

The previous prime is 12157222613. The next prime is 12157222673. The reversal of 12157222642 is 24622275121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24622275121 = 93479 ⋅263399.

It can be written as a sum of positive squares in only one way, i.e., 12157047081 + 175561 = 110259^2 + 419^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12157222598 and 12157222607.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3039305659 + ... + 3039305662.

Almost surely, 2^12157222642 is an apocalyptic number.

12157222642 is a deficient number, since it is larger than the sum of its proper divisors (6078611324).

12157222642 is an equidigital number, since it uses as much as digits as its factorization.

12157222642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6078611323.

The product of its digits is 26880, while the sum is 34.

Adding to 12157222642 its reverse (24622275121), we get a palindrome (36779497763).

The spelling of 12157222642 in words is "twelve billion, one hundred fifty-seven million, two hundred twenty-two thousand, six hundred forty-two".