82815321 has 4 divisors (see below), whose sum is σ = 110420432. Its totient is φ = 55210212.

The previous prime is 82815311. The next prime is 82815349. The reversal of 82815321 is 12351828.

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 not a de Polignac number, because 82815321 - 2¹⁰ = 82814297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82815311) 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, 13802551 + ... + 13802556.

It is an arithmetic number, because the mean of its divisors is an integer number (27605108).

Almost surely, 2^82815321 is an apocalyptic number.

It is an amenable number.

82815321 is a deficient number, since it is larger than the sum of its proper divisors (27605111).

82815321 is a wasteful number, since it uses less digits than its factorization.

82815321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27605110.

The product of its digits is 3840, while the sum is 30.

The square root of 82815321 is about 9100.2923579410. The cubic root of 82815321 is about 435.8832996450.

The spelling of 82815321 in words is "eighty-two million, eight hundred fifteen thousand, three hundred twenty-one".