825669643491 has 48 divisors (see below), whose sum is σ = 1487665071360. Its totient is φ = 428704436160.

The previous prime is 825669643489. The next prime is 825669643523. The reversal of 825669643491 is 194346966528.

825669643491 is a `hidden beast` number, since 8 + 2 + 56 + 6 + 96 + 4 + 3 + 491 = 666.

It is not a de Polignac number, because 825669643491 - 2¹ = 825669643489 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (825669643411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1090665 + ... + 1685493.

It is an arithmetic number, because the mean of its divisors is an integer number (30993022320).

Almost surely, 2^825669643491 is an apocalyptic number.

825669643491 is a deficient number, since it is larger than the sum of its proper divisors (661995427869).

825669643491 is a wasteful number, since it uses less digits than its factorization.

825669643491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596856 (or 596853 counting only the distinct ones).

The product of its digits is 67184640, while the sum is 63.

The spelling of 825669643491 in words is "eight hundred twenty-five billion, six hundred sixty-nine million, six hundred forty-three thousand, four hundred ninety-one".