229639442591821 has 2 divisors, whose sum is σ = 229639442591822. Its totient is φ = 229639442591820.

The previous prime is 229639442591813. The next prime is 229639442591843. The reversal of 229639442591821 is 128195244936922.

229639442591821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 217049797412100 + 12589645179721 = 14732610^2 + 3548189^2 .

It is a cyclic number.

It is not a de Polignac number, because 229639442591821 - 2³ = 229639442591813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (229639442591861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114819721295910 + 114819721295911.

It is an arithmetic number, because the mean of its divisors is an integer number (114819721295911).

Almost surely, 2^{229639442591821} is an apocalyptic number.

It is an amenable number.

229639442591821 is a deficient number, since it is larger than the sum of its proper divisors (1).

229639442591821 is an equidigital number, since it uses as much as digits as its factorization.

229639442591821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 134369280, while the sum is 67.

The spelling of 229639442591821 in words is "two hundred twenty-nine trillion, six hundred thirty-nine billion, four hundred forty-two million, five hundred ninety-one thousand, eight hundred twenty-one".