2157724 has 12 divisors (see below), whose sum is σ = 3898048. Its totient is φ = 1044000.

The previous prime is 2157721. The next prime is 2157731. The reversal of 2157724 is 4277512.

2157724 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 2157692 and 2157701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8577 + ... + 8824.

2^2157724 is an apocalyptic number.

It is an amenable number.

2157724 is a deficient number, since it is larger than the sum of its proper divisors (1740324).

2157724 is a wasteful number, since it uses less digits than its factorization.

2157724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17436 (or 17434 counting only the distinct ones).

The product of its digits is 3920, while the sum is 28.

The square root of 2157724 is about 1468.9193306646. The cubic root of 2157724 is about 129.2206627293.

The spelling of 2157724 in words is "two million, one hundred fifty-seven thousand, seven hundred twenty-four".