2155842 has 64 divisors (see below), whose sum is σ = 5362560. Its totient is φ = 637632.

The previous prime is 2155841. The next prime is 2155849. The reversal of 2155842 is 2485512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25933 + ... + 26015.

It is an arithmetic number, because the mean of its divisors is an integer number (83790).

2^2155842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2155842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2681280).

2155842 is an abundant number, since it is smaller than the sum of its proper divisors (3206718).

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

2155842 is a wasteful number, since it uses less digits than its factorization.

2155842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 138 counting only the distinct ones).

The product of its digits is 3200, while the sum is 27.

The square root of 2155842 is about 1468.2785839206. The cubic root of 2155842 is about 129.1830823858.

The spelling of 2155842 in words is "two million, one hundred fifty-five thousand, eight hundred forty-two".