82505978 has 4 divisors (see below), whose sum is σ = 123758970. Its totient is φ = 41252988.

The previous prime is 82505971. The next prime is 82506007. The reversal of 82505978 is 87950528.

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

It can be written as a sum of positive squares in only one way, i.e., 60481729 + 22024249 = 7777^2 + 4693^2 .

It is not an unprimeable number, because it can be changed into a prime (82505971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20626493 + ... + 20626496.

Almost surely, 2^82505978 is an apocalyptic number.

82505978 is a deficient number, since it is larger than the sum of its proper divisors (41252992).

82505978 is a wasteful number, since it uses less digits than its factorization.

82505978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41252991.

The product of its (nonzero) digits is 201600, while the sum is 44.

The square root of 82505978 is about 9083.2801344008. The cubic root of 82505978 is about 435.3398990484.

The spelling of 82505978 in words is "eighty-two million, five hundred five thousand, nine hundred seventy-eight".