82569978 has 12 divisors (see below), whose sum is σ = 178901658. Its totient is φ = 27523320.

The previous prime is 82569973. The next prime is 82569979. The reversal of 82569978 is 87996528.

It is a happy number.

82569978 is a `hidden beast` number, since 8 + 2 + 569 + 9 + 78 = 666.

It can be written as a sum of positive squares in only one way, i.e., 75742209 + 6827769 = 8703^2 + 2613^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (82569973) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2293593 + ... + 2293628.

Almost surely, 2^82569978 is an apocalyptic number.

82569978 is an abundant number, since it is smaller than the sum of its proper divisors (96331680).

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

82569978 is a wasteful number, since it uses less digits than its factorization.

82569978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4587229 (or 4587226 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 54.

The square root of 82569978 is about 9086.8024078880. The cubic root of 82569978 is about 435.4524345405.

The spelling of 82569978 in words is "eighty-two million, five hundred sixty-nine thousand, nine hundred seventy-eight".