20202021 has 32 divisors (see below), whose sum is σ = 34617600.
Its totient is φ = 11404800.
The previous prime is 20202019. The next prime is 20202029. The reversal of 20202021 is 12020202.
Adding to 20202021 its reverse (12020202), we get a palindrome (32222223).
It is not a de Polignac number, because 20202021 - 21 = 20202019 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (9).
It is a Curzon number.
It is a junction number, because it is equal to n+sod(n) for n = 20201994 and 20202012.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (20202029) by changing a digit.
It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16221 + ... + 17421.
It is an arithmetic number, because the mean of its divisors is an integer number (1081800).
Almost surely, 220202021 is an apocalyptic number.
20202021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.
It is an amenable number.
20202021 is a deficient number, since it is larger than the sum of its proper divisors (14415579).
20202021 is a wasteful number, since it uses less digits than its factorization.
20202021 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1306 (or 1300 counting only the distinct ones).
The product of its (nonzero) digits is 16, while the sum is 9.
The square root of 20202021 is about 4494.6658385246.
The cubic root of 20202021 is about 272.3526504671.
The spelling of 20202021 in words is "twenty million, two hundred two thousand, twenty-one".