242173021 has 4 divisors (see below), whose sum is σ = 242218972. Its totient is φ = 242127072.

The previous prime is 242172991. The next prime is 242173027. The reversal of 242173021 is 120371242.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120371242 = 2 ⋅60185621.

It can be written as a sum of positive squares in 2 ways, for example, as 131102500 + 111070521 = 11450^2 + 10539^2 .

It is a cyclic number.

It is not a de Polignac number, because 242173021 - 2²⁷ = 107955293 is a prime.

It is a super-3 number, since 3×242173021³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 242172983 and 242173001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (242173027) 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, 13866 + ... + 26011.

It is an arithmetic number, because the mean of its divisors is an integer number (60554743).

Almost surely, 2^242173021 is an apocalyptic number.

It is an amenable number.

242173021 is a deficient number, since it is larger than the sum of its proper divisors (45951).

242173021 is an equidigital number, since it uses as much as digits as its factorization.

242173021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45950.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 242173021 is about 15561.9092980264. The cubic root of 242173021 is about 623.3164470310.

The spelling of 242173021 in words is "two hundred forty-two million, one hundred seventy-three thousand, twenty-one".