99981648 has 160 divisors (see below), whose sum is σ = 325673600. Its totient is φ = 29113344.

The previous prime is 99981631. The next prime is 99981649. The reversal of 99981648 is 84618999.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 99981594 and 99981603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99981649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 106236 + ... + 107172.

It is an arithmetic number, because the mean of its divisors is an integer number (2035460).

Almost surely, 2^99981648 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 99981648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162836800).

99981648 is an abundant number, since it is smaller than the sum of its proper divisors (225691952).

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

99981648 is a wasteful number, since it uses less digits than its factorization.

99981648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986 (or 974 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 54.

The square root of 99981648 is about 9999.0823578966. The cubic root of 99981648 is about 464.1304874780.

The spelling of 99981648 in words is "ninety-nine million, nine hundred eighty-one thousand, six hundred forty-eight".