2156440 has 96 divisors (see below), whose sum is σ = 5929200. Its totient is φ = 698880.

The previous prime is 2156437. The next prime is 2156447. The reversal of 2156440 is 446512.

2156440 = T₇₂ + T₇₃ + ... + T₂₃₆.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156447) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74346 + ... + 74374.

2^2156440 is an apocalyptic number.

2156440 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 2156440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2964600).

2156440 is an abundant number, since it is smaller than the sum of its proper divisors (3772760).

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

2156440 is a wasteful number, since it uses less digits than its factorization.

2156440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 2156440 is about 1468.4822096301. The cubic root of 2156440 is about 129.1950258000.

The spelling of 2156440 in words is "two million, one hundred fifty-six thousand, four hundred forty".