1988890 has 16 divisors (see below), whose sum is σ = 3641760. Its totient is φ = 781840.

The previous prime is 1988887. The next prime is 1988891. The reversal of 1988890 is 988891.

It is not an unprimeable number, because it can be changed into a prime (1988891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1096 + ... + 2275.

It is an arithmetic number, because the mean of its divisors is an integer number (227610).

2^1988890 is an apocalyptic number.

1988890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1988890 is a deficient number, since it is larger than the sum of its proper divisors (1652870).

1988890 is a wasteful number, since it uses less digits than its factorization.

1988890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3437.

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 1988890 is about 1410.2801140199. The cubic root of 1988890 is about 125.7583762850.

Subtracting from 1988890 its reverse (988891), we obtain a palindrome (999999).

The spelling of 1988890 in words is "one million, nine hundred eighty-eight thousand, eight hundred ninety".