81322878 has 64 divisors (see below), whose sum is σ = 204503040. Its totient is φ = 20984832.

The previous prime is 81322861. The next prime is 81322897. The reversal of 81322878 is 87822318.

It is a super-2 number, since 2×81322878² = 13226820972405768, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24078 + ... + 27246.

It is an arithmetic number, because the mean of its divisors is an integer number (3195360).

Almost surely, 2^81322878 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81322878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102251520).

81322878 is an abundant number, since it is smaller than the sum of its proper divisors (123180162).

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

81322878 is a wasteful number, since it uses less digits than its factorization.

81322878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3241.

The product of its digits is 43008, while the sum is 39.

The square root of 81322878 is about 9017.9198266563. The cubic root of 81322878 is about 433.2490109432.

The spelling of 81322878 in words is "eighty-one million, three hundred twenty-two thousand, eight hundred seventy-eight".