4281806821 has 4 divisors (see below), whose sum is σ = 4329917100. Its totient is φ = 4233696544.

The previous prime is 4281806803. The next prime is 4281806849. The reversal of 4281806821 is 1286081824.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1053976225 + 3227830596 = 32465^2 + 56814^2 .

It is a cyclic number.

It is not a de Polignac number, because 4281806821 - 2¹³ = 4281798629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4281806621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24055006 + ... + 24055183.

It is an arithmetic number, because the mean of its divisors is an integer number (1082479275).

Almost surely, 2^4281806821 is an apocalyptic number.

It is an amenable number.

4281806821 is a deficient number, since it is larger than the sum of its proper divisors (48110279).

4281806821 is an equidigital number, since it uses as much as digits as its factorization.

4281806821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48110278.

The product of its (nonzero) digits is 49152, while the sum is 40.

The square root of 4281806821 is about 65435.5165105312. The cubic root of 4281806821 is about 1623.8367148644.

The spelling of 4281806821 in words is "four billion, two hundred eighty-one million, eight hundred six thousand, eight hundred twenty-one".