2101990 has 32 divisors (see below), whose sum is σ = 4191264. Its totient is φ = 752640.

The previous prime is 2101961. The next prime is 2102021. The reversal of 2101990 is 991012.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10572 + ... + 10768.

It is an arithmetic number, because the mean of its divisors is an integer number (130977).

2^2101990 is an apocalyptic number.

2101990 is a deficient number, since it is larger than the sum of its proper divisors (2089274).

2101990 is a wasteful number, since it uses less digits than its factorization.

2101990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 2101990 is about 1449.8241272651. The cubic root of 2101990 is about 128.0983537687.

Adding to 2101990 its sum of digits (22), we get a palindrome (2102012).

The spelling of 2101990 in words is "two million, one hundred one thousand, nine hundred ninety".