1987307820 has 144 divisors (see below), whose sum is σ = 6413123808. Its totient is φ = 496404480.

The previous prime is 1987307771. The next prime is 1987307879. The reversal of 1987307820 is 287037891.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 693190 + ... + 696050.

It is an arithmetic number, because the mean of its divisors is an integer number (44535582).

Almost surely, 2^1987307820 is an apocalyptic number.

1987307820 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 1987307820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3206561904).

1987307820 is an abundant number, since it is smaller than the sum of its proper divisors (4425815988).

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

1987307820 is a wasteful number, since it uses less digits than its factorization.

1987307820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3120 (or 3115 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 1987307820 is about 44579.2308143602. The cubic root of 1987307820 is about 1257.2502012948.

The spelling of 1987307820 in words is "one billion, nine hundred eighty-seven million, three hundred seven thousand, eight hundred twenty".