99981229 has 2 divisors, whose sum is σ = 99981230. Its totient is φ = 99981228.

The previous prime is 99981227. The next prime is 99981251. The reversal of 99981229 is 92218999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83997225 + 15984004 = 9165^2 + 3998^2 .

It is a cyclic number.

It is not a de Polignac number, because 99981229 - 2¹ = 99981227 is a prime.

Together with 99981227, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99981221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49990614 + 49990615.

It is an arithmetic number, because the mean of its divisors is an integer number (49990615).

Almost surely, 2^99981229 is an apocalyptic number.

It is an amenable number.

99981229 is a deficient number, since it is larger than the sum of its proper divisors (1).

99981229 is an equidigital number, since it uses as much as digits as its factorization.

99981229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 49.

The square root of 99981229 is about 9999.0614059521. The cubic root of 99981229 is about 464.1298391226.

It can be divided in two parts, 999 and 81229, that added together give a palindrome (82228).

The spelling of 99981229 in words is "ninety-nine million, nine hundred eighty-one thousand, two hundred twenty-nine".