1991392200 has 144 divisors (see below), whose sum is σ = 7643201280. Its totient is φ = 455172480.

The previous prime is 1991392199. The next prime is 1991392201. The reversal of 1991392200 is 22931991.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1991392199) and next prime (1991392201).

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

It is not an unprimeable number, because it can be changed into a prime (1991392201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 66424 + ... + 91623.

Almost surely, 2^1991392200 is an apocalyptic number.

1991392200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1991392200 is an abundant number, since it is smaller than the sum of its proper divisors (5651809080).

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

1991392200 is a wasteful number, since it uses less digits than its factorization.

1991392200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158076 (or 158064 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 36.

The square root of 1991392200 is about 44625.0176470553. The cubic root of 1991392200 is about 1258.1109258059.

The spelling of 1991392200 in words is "one billion, nine hundred ninety-one million, three hundred ninety-two thousand, two hundred".