2105400 has 144 divisors (see below), whose sum is σ = 7421400. Its totient is φ = 492800.

The previous prime is 2105381. The next prime is 2105407. The reversal of 2105400 is 45012.

It is a Cunningham number, because it is equal to 1451²-1.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105407) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 72586 + ... + 72614.

2^2105400 is an apocalyptic number.

2105400 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 2105400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3710700).

2105400 is an abundant number, since it is smaller than the sum of its proper divisors (5316000).

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

2105400 is a wasteful number, since it uses less digits than its factorization.

2105400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 2105400 is about 1450.9996554100. Note that the first 3 decimals coincide. The cubic root of 2105400 is about 128.1675864780.

The spelling of 2105400 in words is "two million, one hundred five thousand, four hundred".