816001644 has 12 divisors (see below), whose sum is σ = 1904003864. Its totient is φ = 272000544.

The previous prime is 816001631. The next prime is 816001673. The reversal of 816001644 is 446100618.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34000057 + ... + 34000080.

Almost surely, 2^816001644 is an apocalyptic number.

It is an amenable number.

816001644 is an abundant number, since it is smaller than the sum of its proper divisors (1088002220).

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

816001644 is a wasteful number, since it uses less digits than its factorization.

816001644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68000144 (or 68000142 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 816001644 is about 28565.7424899126. The cubic root of 816001644 is about 934.4663732285.

The spelling of 816001644 in words is "eight hundred sixteen million, one thousand, six hundred forty-four".