1993648644 has 144 divisors (see below), whose sum is σ = 5757460800. Its totient is φ = 576605952.

The previous prime is 1993648639. The next prime is 1993648651. The reversal of 1993648644 is 4468463991.

It is a happy number.

1993648644 is a `hidden beast` number, since 1 + 99 + 36 + 486 + 44 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1235182 + ... + 1236794.

Almost surely, 2^1993648644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1993648644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2878730400).

1993648644 is an abundant number, since it is smaller than the sum of its proper divisors (3763812156).

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

1993648644 is a wasteful number, since it uses less digits than its factorization.

1993648644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794 (or 1789 counting only the distinct ones).

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

The square root of 1993648644 is about 44650.2927649976. The cubic root of 1993648644 is about 1258.5859344103.

The spelling of 1993648644 in words is "one billion, nine hundred ninety-three million, six hundred forty-eight thousand, six hundred forty-four".