1994368644 has 18 divisors (see below), whose sum is σ = 5041320830. Its totient is φ = 664789536.

The previous prime is 1994368631. The next prime is 1994368661. The reversal of 1994368644 is 4468634991.

It is a happy number.

1994368644 is a `hidden beast` number, since 1 + 99 + 436 + 86 + 44 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1079911044 + 914457600 = 32862^2 + 30240^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27699529 + ... + 27699600.

Almost surely, 2^1994368644 is an apocalyptic number.

It is an amenable number.

1994368644 is an abundant number, since it is smaller than the sum of its proper divisors (3046952186).

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

1994368644 is a wasteful number, since it uses less digits than its factorization.

1994368644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55399139 (or 55399134 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 54.

The square root of 1994368644 is about 44658.3546942787. The cubic root of 1994368644 is about 1258.7374276384.

The spelling of 1994368644 in words is "one billion, nine hundred ninety-four million, three hundred sixty-eight thousand, six hundred forty-four".