81628351 has 8 divisors (see below), whose sum is σ = 98199680. Its totient is φ = 66284568.

The previous prime is 81628307. The next prime is 81628369. The reversal of 81628351 is 15382618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81628351 - 2⁷ = 81628223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81628051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 306741 + ... + 307006.

It is an arithmetic number, because the mean of its divisors is an integer number (12274960).

Almost surely, 2^81628351 is an apocalyptic number.

81628351 is a deficient number, since it is larger than the sum of its proper divisors (16571329).

81628351 is a wasteful number, since it uses less digits than its factorization.

81628351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613773.

The product of its digits is 11520, while the sum is 34.

The square root of 81628351 is about 9034.8409504540. The cubic root of 81628351 is about 433.7908039913.

The spelling of 81628351 in words is "eighty-one million, six hundred twenty-eight thousand, three hundred fifty-one".