1991925000 has 384 divisors, whose sum is σ = 7480771200. Its totient is φ = 488160000.

The previous prime is 1991924999. The next prime is 1991925031. The reversal of 1991925000 is 5291991.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8774887 + ... + 8775113.

It is an arithmetic number, because the mean of its divisors is an integer number (19481175).

Almost surely, 2^1991925000 is an apocalyptic number.

1991925000 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 1991925000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3740385600).

1991925000 is an abundant number, since it is smaller than the sum of its proper divisors (5488846200).

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

1991925000 is a wasteful number, since it uses less digits than its factorization.

1991925000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 1991925000 is about 44630.9869933435. The cubic root of 1991925000 is about 1258.2231189621.

The spelling of 1991925000 in words is "one billion, nine hundred ninety-one million, nine hundred twenty-five thousand".