81629376 has 112 divisors (see below), whose sum is σ = 232074720. Its totient is φ = 25231360.

The previous prime is 81629281. The next prime is 81629411. The reversal of 81629376 is 67392618.

It is a happy number.

It is a super-2 number, since 2×81629376² = 13326710052298752, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 290356 + ... + 290636.

Almost surely, 2^81629376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81629376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116037360).

81629376 is an abundant number, since it is smaller than the sum of its proper divisors (150445344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81629376 is a wasteful number, since it uses less digits than its factorization.

81629376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402 (or 392 counting only the distinct ones).

The product of its digits is 108864, while the sum is 42.

The square root of 81629376 is about 9034.8976751262. The cubic root of 81629376 is about 433.7926196747.

It can be divided in two parts, 816 and 29376, that multiplied together give a square (23970816 = 4896²).

The spelling of 81629376 in words is "eighty-one million, six hundred twenty-nine thousand, three hundred seventy-six".