19820820 has 24 divisors (see below), whose sum is σ = 55498464. Its totient is φ = 5285536.

The previous prime is 19820797. The next prime is 19820821. The reversal of 19820820 is 2802891.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19820821) 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, 165114 + ... + 165233.

It is an arithmetic number, because the mean of its divisors is an integer number (2312436).

Almost surely, 2^19820820 is an apocalyptic number.

19820820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19820820 is an abundant number, since it is smaller than the sum of its proper divisors (35677644).

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

19820820 is a wasteful number, since it uses less digits than its factorization.

19820820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330359 (or 330357 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 19820820 is about 4452.0579511053. The cubic root of 19820820 is about 270.6287131891.

The spelling of 19820820 in words is "nineteen million, eight hundred twenty thousand, eight hundred twenty".