99981388 has 12 divisors (see below), whose sum is σ = 188426560. Its totient is φ = 46145232.

The previous prime is 99981377. The next prime is 99981389. The reversal of 99981388 is 88318999.

It is not an unprimeable number, because it can be changed into a prime (99981389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 961308 + ... + 961411.

Almost surely, 2^99981388 is an apocalyptic number.

It is an amenable number.

99981388 is a deficient number, since it is larger than the sum of its proper divisors (88445172).

99981388 is a wasteful number, since it uses less digits than its factorization.

99981388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1922736 (or 1922734 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 55.

The square root of 99981388 is about 9999.0693566952. The cubic root of 99981388 is about 464.1300851574.

The spelling of 99981388 in words is "ninety-nine million, nine hundred eighty-one thousand, three hundred eighty-eight".