81672330 has 64 divisors (see below), whose sum is σ = 200931840. Its totient is φ = 21240384.

The previous prime is 81672319. The next prime is 81672359. The reversal of 81672330 is 3327618.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 359677 + ... + 359903.

It is an arithmetic number, because the mean of its divisors is an integer number (3139560).

Almost surely, 2^81672330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81672330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100465920).

81672330 is an abundant number, since it is smaller than the sum of its proper divisors (119259510).

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

81672330 is a wasteful number, since it uses less digits than its factorization.

81672330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 81672330 is about 9037.2744785140. The cubic root of 81672330 is about 433.8686946604.

Adding to 81672330 its reverse (3327618), we get a palindrome (84999948).

The spelling of 81672330 in words is "eighty-one million, six hundred seventy-two thousand, three hundred thirty".