198520657920 has 1728 divisors, whose sum is σ = 858681401760. Its totient is φ = 43571478528.

The previous prime is 198520657913. The next prime is 198520657931. The reversal of 198520657920 is 29756025891.

198520657920 is a `hidden beast` number, since 1 + 98 + 520 + 6 + 5 + 7 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 10448455671 + ... + 10448455689.

Almost surely, 2^198520657920 is an apocalyptic number.

198520657920 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 198520657920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (429340700880).

198520657920 is an abundant number, since it is smaller than the sum of its proper divisors (660160743840).

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

198520657920 is a wasteful number, since it uses less digits than its factorization.

198520657920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 198520657920 in words is "one hundred ninety-eight billion, five hundred twenty million, six hundred fifty-seven thousand, nine hundred twenty".