1242558421 has 4 divisors (see below), whose sum is σ = 1338139852. Its totient is φ = 1146976992.

The previous prime is 1242558419. The next prime is 1242558431. The reversal of 1242558421 is 1248552421.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 320768100 + 921790321 = 17910^2 + 30361^2 .

It is a cyclic number.

It is not a de Polignac number, because 1242558421 - 2¹ = 1242558419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242558431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47790696 + ... + 47790721.

It is an arithmetic number, because the mean of its divisors is an integer number (334534963).

Almost surely, 2^1242558421 is an apocalyptic number.

It is an amenable number.

1242558421 is a deficient number, since it is larger than the sum of its proper divisors (95581431).

1242558421 is an equidigital number, since it uses as much as digits as its factorization.

1242558421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95581430.

The product of its digits is 25600, while the sum is 34.

The square root of 1242558421 is about 35249.9421417965. The cubic root of 1242558421 is about 1075.0754361341.

The spelling of 1242558421 in words is "one billion, two hundred forty-two million, five hundred fifty-eight thousand, four hundred twenty-one".