2101890 has 32 divisors (see below), whose sum is σ = 5765760. Its totient is φ = 480384.

The previous prime is 2101873. The next prime is 2101903. The reversal of 2101890 is 981012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an alternating number because its digits alternate between even and odd.

2101890 is a modest number, since divided by 1890 gives 210 as remainder.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4795 + ... + 5214.

It is an arithmetic number, because the mean of its divisors is an integer number (180180).

2^2101890 is an apocalyptic number.

2101890 is an abundant number, since it is smaller than the sum of its proper divisors (3663870).

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

2101890 is a wasteful number, since it uses less digits than its factorization.

2101890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10026.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 2101890 is about 1449.7896399133. The cubic root of 2101890 is about 128.0963223542.

It can be divided in two parts, 210 and 1890, that multiplied together give a square (396900 = 630²).

The spelling of 2101890 in words is "two million, one hundred one thousand, eight hundred ninety".