81171464 has 64 divisors (see below), whose sum is σ = 181958400. Its totient is φ = 33510400.

The previous prime is 81171437. The next prime is 81171469. The reversal of 81171464 is 46417118.

It is a self number, because there is not a number n which added to its sum of digits gives 81171464.

It is not an unprimeable number, because it can be changed into a prime (81171469) 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, 42449 + ... + 44319.

It is an arithmetic number, because the mean of its divisors is an integer number (2843100).

Almost surely, 2^81171464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81171464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90979200).

81171464 is an abundant number, since it is smaller than the sum of its proper divisors (100786936).

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

81171464 is a wasteful number, since it uses less digits than its factorization.

81171464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1934 (or 1930 counting only the distinct ones).

The product of its digits is 5376, while the sum is 32.

The square root of 81171464 is about 9009.5207419707. The cubic root of 81171464 is about 432.9799570076.

The spelling of 81171464 in words is "eighty-one million, one hundred seventy-one thousand, four hundred sixty-four".