81778434 has 32 divisors (see below), whose sum is σ = 174666240. Its totient is φ = 25468800.

The previous prime is 81778423. The next prime is 81778447. The reversal of 81778434 is 43487718.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2187 + ... + 12974.

It is an arithmetic number, because the mean of its divisors is an integer number (5458320).

Almost surely, 2^81778434 is an apocalyptic number.

81778434 is an abundant number, since it is smaller than the sum of its proper divisors (92887806).

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

81778434 is a wasteful number, since it uses less digits than its factorization.

81778434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15226.

The product of its digits is 150528, while the sum is 42.

The square root of 81778434 is about 9043.1429271023. The cubic root of 81778434 is about 434.0564991181.

The spelling of 81778434 in words is "eighty-one million, seven hundred seventy-eight thousand, four hundred thirty-four".