81774434 has 12 divisors (see below), whose sum is σ = 142688214. Its totient is φ = 35046144.

The previous prime is 81774431. The next prime is 81774449. The reversal of 81774434 is 43447718.

It can be written as a sum of positive squares in only one way, i.e., 74736025 + 7038409 = 8645^2 + 2653^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81774431) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 417119 + ... + 417314.

Almost surely, 2^81774434 is an apocalyptic number.

81774434 is a deficient number, since it is larger than the sum of its proper divisors (60913780).

81774434 is a wasteful number, since it uses less digits than its factorization.

81774434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834449 (or 834442 counting only the distinct ones).

The product of its digits is 75264, while the sum is 38.

The square root of 81774434 is about 9042.9217623509. The cubic root of 81774434 is about 434.0494220513.

The spelling of 81774434 in words is "eighty-one million, seven hundred seventy-four thousand, four hundred thirty-four".