19798020 has 180 divisors, whose sum is σ = 68942412. Its totient is φ = 4752000.

The previous prime is 19798003. The next prime is 19798027. The reversal of 19798020 is 2089791.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14152644 + 5645376 = 3762^2 + 2376^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19798027) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 195970 + ... + 196070.

It is a vampire number, since it can be written as 2178 ⋅ 9090 (with its own digits).

Almost surely, 2^19798020 is an apocalyptic number.

19798020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19798020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34471206).

19798020 is an abundant number, since it is smaller than the sum of its proper divisors (49144392).

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

19798020 is a wasteful number, since it uses less digits than its factorization.

19798020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 19798020 is about 4449.4966007404. The cubic root of 19798020 is about 270.5249048015.

19798020 divided by its sum of digits (36) gives a palindrome (549945).

It can be divided in two parts, 1979 and 8020, that added together give a palindrome (9999).

The spelling of 19798020 in words is "nineteen million, seven hundred ninety-eight thousand, twenty".