20002121 has 8 divisors (see below), whose sum is σ = 20420640. Its totient is φ = 19586368.

The previous prime is 20002097. The next prime is 20002123. The reversal of 20002121 is 12120002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20002121 - 2¹⁸ = 19739977 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20002099 and 20002108.

It is not an unprimeable number, because it can be changed into a prime (20002123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19985 + ... + 20961.

It is an arithmetic number, because the mean of its divisors is an integer number (2552580).

Almost surely, 2^20002121 is an apocalyptic number.

It is an amenable number.

20002121 is a deficient number, since it is larger than the sum of its proper divisors (418519).

20002121 is an equidigital number, since it uses as much as digits as its factorization.

20002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1383.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 20002121 is about 4472.3730837219. The cubic root of 20002121 is about 271.4513567866.

Adding to 20002121 its reverse (12120002), we get a palindrome (32122123).

It can be divided in two parts, 20002 and 121, that multiplied together give a palindrome (2420242).

The spelling of 20002121 in words is "twenty million, two thousand, one hundred twenty-one".