989995644 has 36 divisors (see below), whose sum is σ = 2729989080. Its totient is φ = 299998560.

The previous prime is 989995631. The next prime is 989995651. The reversal of 989995644 is 446599989.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 1249599 + ... + 1250390.

It is an arithmetic number, because the mean of its divisors is an integer number (75833030).

Almost surely, 2^989995644 is an apocalyptic number.

It is an amenable number.

989995644 is an abundant number, since it is smaller than the sum of its proper divisors (1739993436).

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

989995644 is a wasteful number, since it uses less digits than its factorization.

989995644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2500010 (or 2500005 counting only the distinct ones).

The product of its digits is 25194240, while the sum is 63.

The square root of 989995644 is about 31464.1962236444. The cubic root of 989995644 is about 996.6540316491.

The spelling of 989995644 in words is "nine hundred eighty-nine million, nine hundred ninety-five thousand, six hundred forty-four".