825811497621 has 16 divisors (see below), whose sum is σ = 1334644845120. Its totient is φ = 500491816560.

The previous prime is 825811497601. The next prime is 825811497671. The reversal of 825811497621 is 126794118528.

825811497621 is a `hidden beast` number, since 8 + 2 + 5 + 8 + 1 + 1 + 4 + 9 + 7 + 621 = 666.

It is not a de Polignac number, because 825811497621 - 2¹⁰ = 825811496597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (825811497601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1390254750 + ... + 1390255343.

It is an arithmetic number, because the mean of its divisors is an integer number (83415302820).

Almost surely, 2^825811497621 is an apocalyptic number.

It is an amenable number.

825811497621 is a deficient number, since it is larger than the sum of its proper divisors (508833347499).

825811497621 is a wasteful number, since it uses less digits than its factorization.

825811497621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2780510113 (or 2780510107 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The spelling of 825811497621 in words is "eight hundred twenty-five billion, eight hundred eleven million, four hundred ninety-seven thousand, six hundred twenty-one".