82778688 has 84 divisors (see below), whose sum is σ = 239229900. Its totient is φ = 27365376.

The previous prime is 82778677. The next prime is 82778693. The reversal of 82778688 is 88687728.

It can be written as a sum of positive squares in 2 ways, for example, as 63489024 + 19289664 = 7968^2 + 4392^2 .

It is a super-2 number, since 2×82778688² = 13704622374002688, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78388 + ... + 79436.

It is an arithmetic number, because the mean of its divisors is an integer number (2847975).

Almost surely, 2^82778688 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 82778688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119614950).

82778688 is an abundant number, since it is smaller than the sum of its proper divisors (156451212).

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

82778688 is a wasteful number, since it uses less digits than its factorization.

82778688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1204 (or 1191 counting only the distinct ones).

The product of its digits is 2408448, while the sum is 54.

The square root of 82778688 is about 9098.2793977763. The cubic root of 82778688 is about 435.8190198004.

The spelling of 82778688 in words is "eighty-two million, seven hundred seventy-eight thousand, six hundred eighty-eight".