1988631720 has 192 divisors, whose sum is σ = 6626964240. Its totient is φ = 517017600.

The previous prime is 1988631691. The next prime is 1988631731. The reversal of 1988631720 is 271368891.

1988631720 is a `hidden beast` number, since 1 + 9 + 8 + 8 + 631 + 7 + 2 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 659154276 + 1329477444 = 25674^2 + 36462^2 .

It is a super-2 number, since 2×1988631720² = 7909312235580316800, which contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3008190 + ... + 3008850.

Almost surely, 2^1988631720 is an apocalyptic number.

1988631720 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 1988631720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3313482120).

1988631720 is an abundant number, since it is smaller than the sum of its proper divisors (4638332520).

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

1988631720 is a wasteful number, since it uses less digits than its factorization.

1988631720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876 (or 869 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 1988631720 is about 44594.0771852048. The cubic root of 1988631720 is about 1257.5293233060.

The spelling of 1988631720 in words is "one billion, nine hundred eighty-eight million, six hundred thirty-one thousand, seven hundred twenty".