1985198720 has 64 divisors (see below), whose sum is σ = 4751843400. Its totient is φ = 793079808.

The previous prime is 1985198711. The next prime is 1985198723. The reversal of 1985198720 is 278915891.

It can be written as a sum of positive squares in 4 ways, for example, as 1223880256 + 761318464 = 34984^2 + 27592^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (1985198723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 708362 + ... + 711158.

Almost surely, 2^1985198720 is an apocalyptic number.

1985198720 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 1985198720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2375921700).

1985198720 is an abundant number, since it is smaller than the sum of its proper divisors (2766644680).

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

1985198720 is a wasteful number, since it uses less digits than its factorization.

1985198720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3925 (or 3913 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 50.

The square root of 1985198720 is about 44555.5688999703. The cubic root of 1985198720 is about 1256.8052769296.

The spelling of 1985198720 in words is "one billion, nine hundred eighty-five million, one hundred ninety-eight thousand, seven hundred twenty".