1242112857 has 4 divisors (see below), whose sum is σ = 1656150480. Its totient is φ = 828075236.

The previous prime is 1242112853. The next prime is 1242112873. The reversal of 1242112857 is 7582112421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1242112857 - 2² = 1242112853 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1242112853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207018807 + ... + 207018812.

It is an arithmetic number, because the mean of its divisors is an integer number (414037620).

Almost surely, 2^1242112857 is an apocalyptic number.

It is an amenable number.

1242112857 is a deficient number, since it is larger than the sum of its proper divisors (414037623).

1242112857 is an equidigital number, since it uses as much as digits as its factorization.

1242112857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414037622.

The product of its digits is 8960, while the sum is 33.

The square root of 1242112857 is about 35243.6215080119. The cubic root of 1242112857 is about 1074.9469184534.

The spelling of 1242112857 in words is "one billion, two hundred forty-two million, one hundred twelve thousand, eight hundred fifty-seven".