81611392 has 32 divisors (see below), whose sum is σ = 163235700. Its totient is φ = 40642560.

The previous prime is 81611389. The next prime is 81611393. The reversal of 81611392 is 29311618.

It can be written as a sum of positive squares in 2 ways, for example, as 78428736 + 3182656 = 8856^2 + 1784^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (81611393) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 34834 + ... + 37102.

Almost surely, 2^81611392 is an apocalyptic number.

It is an amenable number.

81611392 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

81611392 is a wasteful number, since it uses less digits than its factorization.

81611392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2564 (or 2552 counting only the distinct ones).

The product of its digits is 2592, while the sum is 31.

The square root of 81611392 is about 9033.9023683013. The cubic root of 81611392 is about 433.7607606396.

The spelling of 81611392 in words is "eighty-one million, six hundred eleven thousand, three hundred ninety-two".