1999501920 has 576 divisors, whose sum is σ = 7984738944. Its totient is φ = 451215360.

The previous prime is 1999501919. The next prime is 1999501921. The reversal of 1999501920 is 291059991.

It is an interprime number because it is at equal distance from previous prime (1999501919) and next prime (1999501921).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999501921) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 19412589 + ... + 19412691.

It is an arithmetic number, because the mean of its divisors is an integer number (13862394).

Almost surely, 2^1999501920 is an apocalyptic number.

1999501920 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 1999501920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3992369472).

1999501920 is an abundant number, since it is smaller than the sum of its proper divisors (5985237024).

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

1999501920 is a wasteful number, since it uses less digits than its factorization.

1999501920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 65610, while the sum is 45.

The square root of 1999501920 is about 44715.7904995540. The cubic root of 1999501920 is about 1259.8164509652.

The spelling of 1999501920 in words is "one billion, nine hundred ninety-nine million, five hundred one thousand, nine hundred twenty".