82778957 has 4 divisors (see below), whose sum is σ = 83078076. Its totient is φ = 82479840.

The previous prime is 82778923. The next prime is 82778977. The reversal of 82778957 is 75987728.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25110121 + 57668836 = 5011^2 + 7594^2 .

It is a cyclic number.

It is not a de Polignac number, because 82778957 - 2²⁶ = 15670093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 82778899 and 82778908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82778977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149144 + ... + 149697.

It is an arithmetic number, because the mean of its divisors is an integer number (20769519).

Almost surely, 2^82778957 is an apocalyptic number.

It is an amenable number.

82778957 is a deficient number, since it is larger than the sum of its proper divisors (299119).

82778957 is a wasteful number, since it uses less digits than its factorization.

82778957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299118.

The product of its digits is 1975680, while the sum is 53.

The square root of 82778957 is about 9098.2941807792. The cubic root of 82778957 is about 435.8194918832.

The spelling of 82778957 in words is "eighty-two million, seven hundred seventy-eight thousand, nine hundred fifty-seven".