20003121 has 24 divisors (see below), whose sum is σ = 29877120. Its totient is φ = 12888000.

The previous prime is 20003117. The next prime is 20003131. The reversal of 20003121 is 12130002.

It is a happy number.

It is not a de Polignac number, because 20003121 - 2² = 20003117 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (20003131) 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 23 ways as a sum of consecutive naturals, for example, 55540 + ... + 55898.

It is an arithmetic number, because the mean of its divisors is an integer number (1244880).

Almost surely, 2^20003121 is an apocalyptic number.

It is an amenable number.

20003121 is a deficient number, since it is larger than the sum of its proper divisors (9873999).

20003121 is a wasteful number, since it uses less digits than its factorization.

20003121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557 (or 554 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 20003121 is about 4472.4848797956. The cubic root of 20003121 is about 271.4558804207.

Adding to 20003121 its reverse (12130002), we get a palindrome (32133123).

It can be divided in two parts, 200031 and 21, that multiplied together give a triangular number (4200651 = T₂₈₉₈).

The spelling of 20003121 in words is "twenty million, three thousand, one hundred twenty-one".