1801988 has 12 divisors (see below), whose sum is σ = 3183180. Its totient is φ = 892512.

The previous prime is 1801967. The next prime is 1801997. The reversal of 1801988 is 8891081.

It can be written as a sum of positive squares in 2 ways, for example, as 1295044 + 506944 = 1138^2 + 712^2 .

It is a super-5 number, since 5×1801988⁵ (a number of 32 digits) contains 55555 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1631 + ... + 2502.

It is an arithmetic number, because the mean of its divisors is an integer number (265265).

2^1801988 is an apocalyptic number.

It is an amenable number.

1801988 is a deficient number, since it is larger than the sum of its proper divisors (1381192).

1801988 is a wasteful number, since it uses less digits than its factorization.

1801988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4246 (or 4244 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 35.

The square root of 1801988 is about 1342.3814659030. The cubic root of 1801988 is about 121.6888064628.

The spelling of 1801988 in words is "one million, eight hundred one thousand, nine hundred eighty-eight".