815894886361 has 3 divisors (see below), whose sum is σ = 815895789631. Its totient is φ = 815893983092.

The previous prime is 815894886341. The next prime is 815894886371. The reversal of 815894886361 is 163688498518.

The square root of 815894886361 is 903269.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 225179669961 + 590715216400 = 474531^2 + 768580^2 .

It is not a de Polignac number, because 815894886361 - 2⁵ = 815894886329 is a prime.

It is a super-3 number, since 3×815894886361³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (815894886341) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 451635 + ... + 1354903.

Almost surely, 2^815894886361 is an apocalyptic number.

815894886361 is the 903269-th square number.

815894886361 is the 451635-th centered octagonal number.

It is an amenable number.

815894886361 is a deficient number, since it is larger than the sum of its proper divisors (903270).

815894886361 is an frugal number, since it uses more digits than its factorization.

815894886361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806538 (or 903269 counting only the distinct ones).

The product of its digits is 79626240, while the sum is 67.

The spelling of 815894886361 in words is "eight hundred fifteen billion, eight hundred ninety-four million, eight hundred eighty-six thousand, three hundred sixty-one".