1019988 has 36 divisors (see below), whose sum is σ = 2669940. Its totient is φ = 327936.

The previous prime is 1019971. The next prime is 1020001. The reversal of 1019988 is 8899101.

It can be written as a sum of positive squares in 2 ways, for example, as 777924 + 242064 = 882^2 + 492^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 556 + ... + 1532.

It is an arithmetic number, because the mean of its divisors is an integer number (74165).

2^1019988 is an apocalyptic number.

1019988 is a gapful number since it is divisible by the number (18) 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 1019988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1334970).

1019988 is an abundant number, since it is smaller than the sum of its proper divisors (1649952).

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

1019988 is a wasteful number, since it uses less digits than its factorization.

1019988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016 (or 1011 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 1019988 is about 1009.9445529335. The cubic root of 1019988 is about 100.6618762005.

The spelling of 1019988 in words is "one million, nineteen thousand, nine hundred eighty-eight".