81193829 has 2 divisors, whose sum is σ = 81193830. Its totient is φ = 81193828.

The previous prime is 81193813. The next prime is 81193831. The reversal of 81193829 is 92839118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80550625 + 643204 = 8975^2 + 802^2 .

It is a cyclic number.

It is not a de Polignac number, because 81193829 - 2⁴ = 81193813 is a prime.

Together with 81193831, 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 (81193729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40596914 + 40596915.

It is an arithmetic number, because the mean of its divisors is an integer number (40596915).

Almost surely, 2^81193829 is an apocalyptic number.

It is an amenable number.

81193829 is a deficient number, since it is larger than the sum of its proper divisors (1).

81193829 is an equidigital number, since it uses as much as digits as its factorization.

81193829 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 41.

The square root of 81193829 is about 9010.7618434847. The cubic root of 81193829 is about 433.0197193700.

The spelling of 81193829 in words is "eighty-one million, one hundred ninety-three thousand, eight hundred twenty-nine".