81400418 has 16 divisors (see below), whose sum is σ = 134054784. Its totient is φ = 36762960.

The previous prime is 81400409. The next prime is 81400433.

81400418 is nontrivially palindromic in base 10.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8330 + ... + 15237.

It is an arithmetic number, because the mean of its divisors is an integer number (8378424).

Almost surely, 2^81400418 is an apocalyptic number.

81400418 is a deficient number, since it is larger than the sum of its proper divisors (52654366).

81400418 is a wasteful number, since it uses less digits than its factorization.

81400418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23737.

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 81400418 is about 9022.2180199771. The cubic root of 81400418 is about 433.3866657567.

It can be divided in two parts, 81400 and 418, that added together give a palindrome (81818).

The spelling of 81400418 in words is "eighty-one million, four hundred thousand, four hundred eighteen".