242173781 has 4 divisors (see below), whose sum is σ = 242621964. Its totient is φ = 241725600.

The previous prime is 242173759. The next prime is 242173783. The reversal of 242173781 is 187371242.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187371242 = 2 ⋅93685621.

It can be written as a sum of positive squares in 2 ways, for example, as 45024100 + 197149681 = 6710^2 + 14041^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-242173781 is a prime.

It is a super-2 number, since 2×242173781² = 117296280407671922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (242173783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223280 + ... + 224361.

It is an arithmetic number, because the mean of its divisors is an integer number (60655491).

Almost surely, 2^242173781 is an apocalyptic number.

It is an amenable number.

242173781 is a deficient number, since it is larger than the sum of its proper divisors (448183).

242173781 is an equidigital number, since it uses as much as digits as its factorization.

242173781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448182.

The product of its digits is 18816, while the sum is 35.

The square root of 242173781 is about 15561.9337166048. The cubic root of 242173781 is about 623.3170990717.

The spelling of 242173781 in words is "two hundred forty-two million, one hundred seventy-three thousand, seven hundred eighty-one".