19981888 has 14 divisors (see below), whose sum is σ = 39651686. Its totient is φ = 9990912.

The previous prime is 19981873. The next prime is 19981889. The reversal of 19981888 is 88818991.

It can be written as a sum of positive squares in only one way, i.e., 19289664 + 692224 = 4392^2 + 832^2 .

It is not an unprimeable number, because it can be changed into a prime (19981889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156045 + ... + 156172.

Almost surely, 2^19981888 is an apocalyptic number.

It is an amenable number.

19981888 is a deficient number, since it is larger than the sum of its proper divisors (19669798).

19981888 is an equidigital number, since it uses as much as digits as its factorization.

19981888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312229 (or 312219 counting only the distinct ones).

The product of its digits is 331776, while the sum is 52.

The square root of 19981888 is about 4470.1105131753. The cubic root of 19981888 is about 271.3597976925.

The spelling of 19981888 in words is "nineteen million, nine hundred eighty-one thousand, eight hundred eighty-eight".