819897639522 has 64 divisors (see below), whose sum is σ = 1800473947776. Its totient is φ = 247381793280.

The previous prime is 819897639391. The next prime is 819897639541. The reversal of 819897639522 is 225936798918.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 568897 + ... + 1401227.

It is an arithmetic number, because the mean of its divisors is an integer number (28132405434).

Almost surely, 2^819897639522 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 819897639522, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (900236973888).

819897639522 is an abundant number, since it is smaller than the sum of its proper divisors (980576308254).

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

819897639522 is a wasteful number, since it uses less digits than its factorization.

819897639522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832595.

The product of its digits is 117573120, while the sum is 69.

The spelling of 819897639522 in words is "eight hundred nineteen billion, eight hundred ninety-seven million, six hundred thirty-nine thousand, five hundred twenty-two".