81210328 has 32 divisors (see below), whose sum is σ = 157829760. Its totient is φ = 39133440.

The previous prime is 81210323. The next prime is 81210329. The reversal of 81210328 is 82301218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81210323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78100 + ... + 79132.

It is an arithmetic number, because the mean of its divisors is an integer number (4932180).

Almost surely, 2^81210328 is an apocalyptic number.

It is an amenable number.

81210328 is a deficient number, since it is larger than the sum of its proper divisors (76619432).

81210328 is a wasteful number, since it uses less digits than its factorization.

81210328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1387 (or 1383 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 81210328 is about 9011.6773133529. The cubic root of 81210328 is about 433.0490479884.

The spelling of 81210328 in words is "eighty-one million, two hundred ten thousand, three hundred twenty-eight".