81400730 has 16 divisors (see below), whose sum is σ = 151248384. Its totient is φ = 31509840.

The previous prime is 81400729. The next prime is 81400799. The reversal of 81400730 is 3700418.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81400696 and 81400705.

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 7 ways as a sum of consecutive naturals, for example, 130982 + ... + 131601.

It is an arithmetic number, because the mean of its divisors is an integer number (9453024).

Almost surely, 2^81400730 is an apocalyptic number.

81400730 is a deficient number, since it is larger than the sum of its proper divisors (69847654).

81400730 is a wasteful number, since it uses less digits than its factorization.

81400730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262621.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 81400730 is about 9022.2353106090. The cubic root of 81400730 is about 433.3872194658.

The spelling of 81400730 in words is "eighty-one million, four hundred thousand, seven hundred thirty".