81438434 has 16 divisors (see below), whose sum is σ = 152300736. Its totient is φ = 31729200.

The previous prime is 81438419. The next prime is 81438437. The reversal of 81438434 is 43483418.

It is a junction number, because it is equal to n+sod(n) for n = 81438394 and 81438403.

It is not an unprimeable number, because it can be changed into a prime (81438437) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 264257 + ... + 264564.

It is an arithmetic number, because the mean of its divisors is an integer number (9518796).

Almost surely, 2^81438434 is an apocalyptic number.

81438434 is a deficient number, since it is larger than the sum of its proper divisors (70862302).

81438434 is a wasteful number, since it uses less digits than its factorization.

81438434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528841.

The product of its digits is 36864, while the sum is 35.

The square root of 81438434 is about 9024.3245730636. The cubic root of 81438434 is about 433.4541226720.

It can be divided in two parts, 814384 and 34, that added together give a palindrome (814418).

The spelling of 81438434 in words is "eighty-one million, four hundred thirty-eight thousand, four hundred thirty-four".