1989575388 has 36 divisors (see below), whose sum is σ = 5065398520. Its totient is φ = 658418976.

The previous prime is 1989575383. The next prime is 1989575407. The reversal of 1989575388 is 8835759891.

1989575388 is a `hidden beast` number, since 1 + 9 + 8 + 95 + 7 + 538 + 8 = 666.

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

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989575383) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 193795 + ... + 203802.

Almost surely, 2^1989575388 is an apocalyptic number.

1989575388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1989575388 is an abundant number, since it is smaller than the sum of its proper divisors (3075823132).

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

1989575388 is a wasteful number, since it uses less digits than its factorization.

1989575388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397746 (or 397741 counting only the distinct ones).

The product of its digits is 21772800, while the sum is 63.

The square root of 1989575388 is about 44604.6565730530. The cubic root of 1989575388 is about 1257.7282041934.

The spelling of 1989575388 in words is "one billion, nine hundred eighty-nine million, five hundred seventy-five thousand, three hundred eighty-eight".