2117840 has 40 divisors (see below), whose sum is σ = 5142528. Its totient is φ = 809600.

The previous prime is 2117833. The next prime is 2117849. The reversal of 2117840 is 487112.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2117849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1265 + ... + 2415.

2^2117840 is an apocalyptic number.

2117840 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 2117840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2571264).

2117840 is an abundant number, since it is smaller than the sum of its proper divisors (3024688).

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

2117840 is a wasteful number, since it uses less digits than its factorization.

2117840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1187 (or 1181 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 2117840 is about 1455.2800417789. The cubic root of 2117840 is about 128.4195219458.

The spelling of 2117840 in words is "two million, one hundred seventeen thousand, eight hundred forty".