2097821565 has 96 divisors (see below), whose sum is σ = 4356696960. Its totient is φ = 954955008.

The previous prime is 2097821549. The next prime is 2097821591. The reversal of 2097821565 is 5651287902.

2097821565 is a `hidden beast` number, since 2 + 0 + 9 + 7 + 82 + 1 + 565 = 666.

It is not a de Polignac number, because 2097821565 - 2⁴ = 2097821549 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 2097821565.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2030289 + ... + 2031321.

It is an arithmetic number, because the mean of its divisors is an integer number (45382260).

Almost surely, 2^2097821565 is an apocalyptic number.

It is an amenable number.

2097821565 is an abundant number, since it is smaller than the sum of its proper divisors (2258875395).

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

2097821565 is a wasteful number, since it uses less digits than its factorization.

2097821565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368 (or 1355 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The square root of 2097821565 is about 45801.9821077647. The cubic root of 2097821565 is about 1280.1362088531.

The spelling of 2097821565 in words is "two billion, ninety-seven million, eight hundred twenty-one thousand, five hundred sixty-five".