81400328 has 32 divisors (see below), whose sum is σ = 155040600. Its totient is φ = 40061952.

The previous prime is 81400307. The next prime is 81400337. The reversal of 81400328 is 82300418.

It can be written as a sum of positive squares in 4 ways, for example, as 56220004 + 25180324 = 7498^2 + 5018^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81400297 and 81400306.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241376 + ... + 241712.

Almost surely, 2^81400328 is an apocalyptic number.

It is an amenable number.

81400328 is a deficient number, since it is larger than the sum of its proper divisors (73640272).

81400328 is a wasteful number, since it uses less digits than its factorization.

81400328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729 (or 725 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 81400328 is about 9022.2130322887. The cubic root of 81400328 is about 433.3865060326.

The spelling of 81400328 in words is "eighty-one million, four hundred thousand, three hundred twenty-eight".