81122688 has 64 divisors (see below), whose sum is σ = 239434800. Its totient is φ = 27039744.

The previous prime is 81122687. The next prime is 81122707. The reversal of 81122688 is 88622118.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81122681) 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, 8281 + ... + 15192.

Almost surely, 2^81122688 is an apocalyptic number.

It is an amenable number.

81122688 is an abundant number, since it is smaller than the sum of its proper divisors (158312112).

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

81122688 is a wasteful number, since it uses less digits than its factorization.

81122688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23496 (or 23478 counting only the distinct ones).

The product of its digits is 12288, while the sum is 36.

The square root of 81122688 is about 9006.8134209608. The cubic root of 81122688 is about 432.8932136255.

It can be divided in two parts, 81122 and 688, that added together give a triangular number (81810 = T₄₀₄).

The spelling of 81122688 in words is "eighty-one million, one hundred twenty-two thousand, six hundred eighty-eight".