81211434 has 32 divisors (see below), whose sum is σ = 174958080. Its totient is φ = 25047792.

The previous prime is 81211421. The next prime is 81211439. The reversal of 81211434 is 43411218.

It is not an unprimeable number, because it can be changed into a prime (81211439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3382 + ... + 13185.

It is an arithmetic number, because the mean of its divisors is an integer number (5467440).

Almost surely, 2^81211434 is an apocalyptic number.

81211434 is an abundant number, since it is smaller than the sum of its proper divisors (93746646).

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

81211434 is a wasteful number, since it uses less digits than its factorization.

81211434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16634.

The product of its digits is 768, while the sum is 24.

The square root of 81211434 is about 9011.7386779689. The cubic root of 81211434 is about 433.0510138716.

It can be divided in two parts, 812 and 11434, that added together give a triangular number (12246 = T₁₅₆).

The spelling of 81211434 in words is "eighty-one million, two hundred eleven thousand, four hundred thirty-four".