1242123999 has 8 divisors (see below), whose sum is σ = 1657906992. Its totient is φ = 827211840.

The previous prime is 1242123979. The next prime is 1242124007. The reversal of 1242123999 is 9993212421.

1242123999 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1242123999 - 2¹² = 1242119903 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 1242123999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242123959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 214372 + ... + 220089.

It is an arithmetic number, because the mean of its divisors is an integer number (207238374).

Almost surely, 2^1242123999 is an apocalyptic number.

1242123999 is a deficient number, since it is larger than the sum of its proper divisors (415782993).

1242123999 is an equidigital number, since it uses as much as digits as its factorization.

1242123999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435417.

The product of its digits is 69984, while the sum is 42.

The square root of 1242123999 is about 35243.7795788136. The cubic root of 1242123999 is about 1074.9501326065.

The spelling of 1242123999 in words is "one billion, two hundred forty-two million, one hundred twenty-three thousand, nine hundred ninety-nine".