19981280 has 48 divisors (see below), whose sum is σ = 51501744. Its totient is φ = 7265280.

The previous prime is 19981249. The next prime is 19981289. The reversal of 19981280 is 8218991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19981289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3917 + ... + 7436.

It is an arithmetic number, because the mean of its divisors is an integer number (1072953).

Almost surely, 2^19981280 is an apocalyptic number.

19981280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19981280 is an abundant number, since it is smaller than the sum of its proper divisors (31520464).

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

19981280 is a wasteful number, since it uses less digits than its factorization.

19981280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11379 (or 11371 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 19981280 is about 4470.0425053907. The cubic root of 19981280 is about 271.3570453929.

The spelling of 19981280 in words is "nineteen million, nine hundred eighty-one thousand, two hundred eighty".