81629836 has 24 divisors (see below), whose sum is σ = 146651904. Its totient is φ = 39743760.

The previous prime is 81629827. The next prime is 81629837. The reversal of 81629836 is 63892618.

It is a junction number, because it is equal to n+sod(n) for n = 81629792 and 81629801.

It is not an unprimeable number, because it can be changed into a prime (81629837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21841 + ... + 25303.

It is an arithmetic number, because the mean of its divisors is an integer number (6110496).

Almost surely, 2^81629836 is an apocalyptic number.

It is an amenable number.

81629836 is a deficient number, since it is larger than the sum of its proper divisors (65022068).

81629836 is a wasteful number, since it uses less digits than its factorization.

81629836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3621 (or 3619 counting only the distinct ones).

The product of its digits is 124416, while the sum is 43.

The square root of 81629836 is about 9034.9231319364. The cubic root of 81629836 is about 433.7934345130.

The spelling of 81629836 in words is "eighty-one million, six hundred twenty-nine thousand, eight hundred thirty-six".