1990188 has 36 divisors (see below), whose sum is σ = 5121480. Its totient is φ = 651456.

The previous prime is 1990187. The next prime is 1990189. The reversal of 1990188 is 8810991.

It is an interprime number because it is at equal distance from previous prime (1990187) and next prime (1990189).

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 not an unprimeable number, because it can be changed into a prime (1990187) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1656 + ... + 2592.

2^1990188 is an apocalyptic number.

1990188 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 1990188, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2560740).

1990188 is an abundant number, since it is smaller than the sum of its proper divisors (3131292).

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

1990188 is a wasteful number, since it uses less digits than its factorization.

1990188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006 (or 1001 counting only the distinct ones).

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

The square root of 1990188 is about 1410.7402312261. The cubic root of 1990188 is about 125.7857280365.

The spelling of 1990188 in words is "one million, nine hundred ninety thousand, one hundred eighty-eight".