631821000816 has 80 divisors (see below), whose sum is σ = 1814036473600. Its totient is φ = 210551700672.

The previous prime is 631821000809. The next prime is 631821000823. The reversal of 631821000816 is 618000128136.

631821000816 is a `hidden beast` number, since 631 + 8 + 2 + 1 + 0 + 0 + 0 + 8 + 16 = 666.

It is an interprime number because it is at equal distance from previous prime (631821000809) and next prime (631821000823).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 15 ways as a sum of consecutive naturals, for example, 1471815 + ... + 1851993.

It is an arithmetic number, because the mean of its divisors is an integer number (22675455920).

Almost surely, 2^631821000816 is an apocalyptic number.

It is an amenable number.

631821000816 is an abundant number, since it is smaller than the sum of its proper divisors (1182215472784).

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

631821000816 is a wasteful number, since it uses less digits than its factorization.

631821000816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384043 (or 384031 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The spelling of 631821000816 in words is "six hundred thirty-one billion, eight hundred twenty-one million, eight hundred sixteen", and thus it is an aban number.