242120455021 has 4 divisors (see below), whose sum is σ = 247271954112. Its totient is φ = 236968955932.

The previous prime is 242120455009. The next prime is 242120455033. The reversal of 242120455021 is 120554021242.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (242120455009) and next prime (242120455033).

It is a cyclic number.

It is not a de Polignac number, because 242120455021 - 2¹³ = 242120446829 is a prime.

It is a super-2 number, since 2×242120455021² (a number of 24 digits) 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 (242120455081) 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, 2575749475 + ... + 2575749568.

It is an arithmetic number, because the mean of its divisors is an integer number (61817988528).

Almost surely, 2^242120455021 is an apocalyptic number.

It is an amenable number.

242120455021 is a deficient number, since it is larger than the sum of its proper divisors (5151499091).

242120455021 is an equidigital number, since it uses as much as digits as its factorization.

242120455021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5151499090.

The product of its (nonzero) digits is 6400, while the sum is 28.

Adding to 242120455021 its reverse (120554021242), we get a palindrome (362674476263).

The spelling of 242120455021 in words is "two hundred forty-two billion, one hundred twenty million, four hundred fifty-five thousand, twenty-one".