2153640 has 64 divisors (see below), whose sum is σ = 6557760. Its totient is φ = 565760.

The previous prime is 2153639. The next prime is 2153647. The reversal of 2153640 is 463512.

It is a happy number.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2153647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15652 + ... + 15788.

It is an arithmetic number, because the mean of its divisors is an integer number (102465).

2^2153640 is an apocalyptic number.

2153640 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 2153640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3278880).

2153640 is an abundant number, since it is smaller than the sum of its proper divisors (4404120).

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

2153640 is a wasteful number, since it uses less digits than its factorization.

2153640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 2153640 is about 1467.5285346459. The cubic root of 2153640 is about 129.1390844100.

The spelling of 2153640 in words is "two million, one hundred fifty-three thousand, six hundred forty".