19881020 has 12 divisors (see below), whose sum is σ = 41750184. Its totient is φ = 7952400.

The previous prime is 19881019. The next prime is 19881077. The reversal of 19881020 is 2018891.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 497006 + ... + 497045.

It is an arithmetic number, because the mean of its divisors is an integer number (3479182).

Almost surely, 2^19881020 is an apocalyptic number.

19881020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19881020 is an abundant number, since it is smaller than the sum of its proper divisors (21869164).

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

19881020 is a wasteful number, since it uses less digits than its factorization.

19881020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 994060 (or 994058 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 19881020 is about 4458.8137435870. The cubic root of 19881020 is about 270.9024217169.

It can be divided in two parts, 198 and 81020, that added together give a palindrome (81218).

The spelling of 19881020 in words is "nineteen million, eight hundred eighty-one thousand, twenty".