20041821 has 24 divisors (see below), whose sum is σ = 29652480. Its totient is φ = 13041600.

The previous prime is 20041817. The next prime is 20041859. The reversal of 20041821 is 12814002.

It is not a de Polignac number, because 20041821 - 2² = 20041817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20041794 and 20041803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20041811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104836 + ... + 105026.

It is an arithmetic number, because the mean of its divisors is an integer number (1235520).

Almost surely, 2^20041821 is an apocalyptic number.

It is an amenable number.

20041821 is a deficient number, since it is larger than the sum of its proper divisors (9610659).

20041821 is a wasteful number, since it uses less digits than its factorization.

20041821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 20041821 is about 4476.8092431999. The cubic root of 20041821 is about 271.6308293692.

Adding to 20041821 its reverse (12814002), we get a palindrome (32855823).

The spelling of 20041821 in words is "twenty million, forty-one thousand, eight hundred twenty-one".