4100821 has 8 divisors (see below), whose sum is σ = 4247640. Its totient is φ = 3955968.

The previous prime is 4100819. The next prime is 4100849. The reversal of 4100821 is 1280014.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2436721 + 1664100 = 1561^2 + 1290^2 .

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 4100821 - 2¹ = 4100819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4100795 and 4100804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4100881) 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 7 ways as a sum of consecutive naturals, for example, 4665 + ... + 5473.

It is an arithmetic number, because the mean of its divisors is an integer number (530955).

Almost surely, 2^4100821 is an apocalyptic number.

It is an amenable number.

4100821 is a deficient number, since it is larger than the sum of its proper divisors (146819).

4100821 is a wasteful number, since it uses less digits than its factorization.

4100821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 4100821 is about 2025.0483944835. The cubic root of 4100821 is about 160.0627488254.

Adding to 4100821 its reverse (1280014), we get a palindrome (5380835).

It can be divided in two parts, 41008 and 21, that multiplied together give a palindrome (861168).

The spelling of 4100821 in words is "four million, one hundred thousand, eight hundred twenty-one".