1999542456 has 128 divisors (see below), whose sum is σ = 5778432000. Its totient is φ = 640089216.

The previous prime is 1999542437. The next prime is 1999542469. The reversal of 1999542456 is 6542459991.

1999542456 is a `hidden beast` number, since 1 + 9 + 99 + 542 + 4 + 5 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 629785 + ... + 632951.

It is an arithmetic number, because the mean of its divisors is an integer number (45144000).

Almost surely, 2^1999542456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999542456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2889216000).

1999542456 is an abundant number, since it is smaller than the sum of its proper divisors (3778889544).

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

1999542456 is a wasteful number, since it uses less digits than its factorization.

1999542456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3298 (or 3288 counting only the distinct ones).

The product of its digits is 3499200, while the sum is 54.

The square root of 1999542456 is about 44716.2437599582. The cubic root of 1999542456 is about 1259.8249643478.

The spelling of 1999542456 in words is "one billion, nine hundred ninety-nine million, five hundred forty-two thousand, four hundred fifty-six".