82631209 has 4 divisors (see below), whose sum is σ = 86980240. Its totient is φ = 78282180.

The previous prime is 82631177. The next prime is 82631221. The reversal of 82631209 is 90213628.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 82631209 - 2⁵ = 82631177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82631239) 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, 2174487 + ... + 2174524.

It is an arithmetic number, because the mean of its divisors is an integer number (21745060).

Almost surely, 2^82631209 is an apocalyptic number.

It is an amenable number.

82631209 is a deficient number, since it is larger than the sum of its proper divisors (4349031).

82631209 is a wasteful number, since it uses less digits than its factorization.

82631209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4349030.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 82631209 is about 9090.1710104926. The cubic root of 82631209 is about 435.5600466959.

The spelling of 82631209 in words is "eighty-two million, six hundred thirty-one thousand, two hundred nine".