1191920400 has 480 divisors, whose sum is σ = 4723507200. Its totient is φ = 283046400.

The previous prime is 1191920377. The next prime is 1191920417. The reversal of 1191920400 is 40291911.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 9385137 + ... + 9385263.

It is an arithmetic number, because the mean of its divisors is an integer number (9840640).

Almost surely, 2^1191920400 is an apocalyptic number.

1191920400 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 1191920400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2361753600).

1191920400 is an abundant number, since it is smaller than the sum of its proper divisors (3531586800).

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

1191920400 is a wasteful number, since it uses less digits than its factorization.

1191920400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 1191920400 is about 34524.2002079701. The cubic root of 1191920400 is about 1060.2682363763.

The spelling of 1191920400 in words is "one billion, one hundred ninety-one million, nine hundred twenty thousand, four hundred".