1198721920 has 128 divisors (see below), whose sum is σ = 3203232480. Its totient is φ = 425164800.

The previous prime is 1198721911. The next prime is 1198721933. The reversal of 1198721920 is 291278911.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (40).

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 15 ways as a sum of consecutive naturals, for example, 286564 + ... + 290716.

Almost surely, 2^1198721920 is an apocalyptic number.

1198721920 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 1198721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1601616240).

1198721920 is an abundant number, since it is smaller than the sum of its proper divisors (2004510560).

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

1198721920 is a wasteful number, since it uses less digits than its factorization.

1198721920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4224 (or 4212 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 40.

The square root of 1198721920 is about 34622.5637410057. The cubic root of 1198721920 is about 1062.2811677583.

The spelling of 1198721920 in words is "one billion, one hundred ninety-eight million, seven hundred twenty-one thousand, nine hundred twenty".