2161900 has 36 divisors (see below), whose sum is σ = 5055232. Its totient is φ = 797760.

The previous prime is 2161897. The next prime is 2161903. The reversal of 2161900 is 91612.

It is an interprime number because it is at equal distance from previous prime (2161897) and next prime (2161903).

It is a super-2 number, since 2×2161900² = 9347623220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161903) 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, 469 + ... + 2131.

2^2161900 is an apocalyptic number.

2161900 is a gapful number since it is divisible by the number (20) 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 2161900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2527616).

2161900 is an abundant number, since it is smaller than the sum of its proper divisors (2893332).

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

2161900 is a wasteful number, since it uses less digits than its factorization.

2161900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1690 (or 1683 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 2161900 is about 1470.3400967123. The cubic root of 2161900 is about 129.3039723858.

It can be divided in two parts, 216 and 1900, that added together give a square (2116 = 46²).

The spelling of 2161900 in words is "two million, one hundred sixty-one thousand, nine hundred".