19881930 has 32 divisors (see below), whose sum is σ = 48326400. Its totient is φ = 5234112.

The previous prime is 19881929. The next prime is 19881941. The reversal of 19881930 is 3918891.

It is a happy number.

It is a super-2 number, since 2×19881930² = 790582281049800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1825 + ... + 6564.

It is an arithmetic number, because the mean of its divisors is an integer number (1510200).

Almost surely, 2^19881930 is an apocalyptic number.

19881930 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19881930 is an abundant number, since it is smaller than the sum of its proper divisors (28444470).

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

19881930 is a wasteful number, since it uses less digits than its factorization.

19881930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8478.

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 19881930 is about 4458.9157874981. The cubic root of 19881930 is about 270.9065549294.

It can be divided in two parts, 198 and 81930, that added together give a palindrome (82128).

The spelling of 19881930 in words is "nineteen million, eight hundred eighty-one thousand, nine hundred thirty".