1242155059 has 4 divisors (see below), whose sum is σ = 1243000960. Its totient is φ = 1241309160.

The previous prime is 1242155053. The next prime is 1242155071. The reversal of 1242155059 is 9505512421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9505512421 = 65129 ⋅145949.

It is a cyclic number.

It is not a de Polignac number, because 1242155059 - 2⁷ = 1242154931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242155053) 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, 420744 + ... + 423685.

It is an arithmetic number, because the mean of its divisors is an integer number (310750240).

Almost surely, 2^1242155059 is an apocalyptic number.

1242155059 is a deficient number, since it is larger than the sum of its proper divisors (845901).

1242155059 is an equidigital number, since it uses as much as digits as its factorization.

1242155059 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845900.

The product of its (nonzero) digits is 18000, while the sum is 34.

The square root of 1242155059 is about 35244.2202211937. The cubic root of 1242155059 is about 1074.9590924401.

The spelling of 1242155059 in words is "one billion, two hundred forty-two million, one hundred fifty-five thousand, fifty-nine".