89729821 has 2 divisors, whose sum is σ = 89729822. Its totient is φ = 89729820.

The previous prime is 89729819. The next prime is 89729867. The reversal of 89729821 is 12892798.

It is an a-pointer prime, because the next prime (89729867) can be obtained adding 89729821 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74822500 + 14907321 = 8650^2 + 3861^2 .

It is a cyclic number.

It is not a de Polignac number, because 89729821 - 2¹ = 89729819 is a prime.

Together with 89729819, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (89529821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 44864910 + 44864911.

It is an arithmetic number, because the mean of its divisors is an integer number (44864911).

Almost surely, 2^89729821 is an apocalyptic number.

It is an amenable number.

89729821 is a deficient number, since it is larger than the sum of its proper divisors (1).

89729821 is an equidigital number, since it uses as much as digits as its factorization.

89729821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 46.

The square root of 89729821 is about 9472.5825939920. The cubic root of 89729821 is about 447.6915875958.

The spelling of 89729821 in words is "eighty-nine million, seven hundred twenty-nine thousand, eight hundred twenty-one".