43722821 has 2 divisors, whose sum is σ = 43722822. Its totient is φ = 43722820.

The previous prime is 43722797. The next prime is 43722853. The reversal of 43722821 is 12822734.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28238596 + 15484225 = 5314^2 + 3935^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43722821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43722871) 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 as a sum of consecutive naturals, namely, 21861410 + 21861411.

It is an arithmetic number, because the mean of its divisors is an integer number (21861411).

Almost surely, 2^43722821 is an apocalyptic number.

It is an amenable number.

43722821 is a deficient number, since it is larger than the sum of its proper divisors (1).

43722821 is an equidigital number, since it uses as much as digits as its factorization.

43722821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 29.

The square root of 43722821 is about 6612.3234191924. The cubic root of 43722821 is about 352.2919544282.

The spelling of 43722821 in words is "forty-three million, seven hundred twenty-two thousand, eight hundred twenty-one".