202042021 has 4 divisors (see below), whose sum is σ = 202614732. Its totient is φ = 201469312.

The previous prime is 202041949. The next prime is 202042039. The reversal of 202042021 is 120240202.

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 82992100 + 119049921 = 9110^2 + 10911^2 .

It is a cyclic number.

It is not a de Polignac number, because 202042021 - 2⁷ = 202041893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202041992 and 202042010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202040021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 285826 + ... + 286531.

It is an arithmetic number, because the mean of its divisors is an integer number (50653683).

Almost surely, 2^202042021 is an apocalyptic number.

It is an amenable number.

202042021 is a deficient number, since it is larger than the sum of its proper divisors (572711).

202042021 is an equidigital number, since it uses as much as digits as its factorization.

202042021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 572710.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 202042021 is about 14214.1486203008. The cubic root of 202042021 is about 586.7871139504.

Adding to 202042021 its reverse (120240202), we get a palindrome (322282223).

It can be divided in two parts, 20 and 2042021, that added together give a square (2042041 = 1429²).

The spelling of 202042021 in words is "two hundred two million, forty-two thousand, twenty-one".