242423021 has 2 divisors, whose sum is σ = 242423022. Its totient is φ = 242423020.

The previous prime is 242423011. The next prime is 242423023. The reversal of 242423021 is 120324242.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179854921 + 62568100 = 13411^2 + 7910^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-242423021 is a prime.

It is a super-2 number, since 2×242423021² = 117537842221532882, which contains 22 as substring.

Together with 242423023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 242422984 and 242423002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (242423023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121211510 + 121211511.

It is an arithmetic number, because the mean of its divisors is an integer number (121211511).

Almost surely, 2^242423021 is an apocalyptic number.

It is an amenable number.

242423021 is a deficient number, since it is larger than the sum of its proper divisors (1).

242423021 is an equidigital number, since it uses as much as digits as its factorization.

242423021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 242423021 is about 15569.9396594849. The cubic root of 242423021 is about 623.5308605661.

Adding to 242423021 its reverse (120324242), we get a palindrome (362747263).

The spelling of 242423021 in words is "two hundred forty-two million, four hundred twenty-three thousand, twenty-one".