2157647 has 4 divisors (see below), whose sum is σ = 2163720. Its totient is φ = 2151576.

The previous prime is 2157641. The next prime is 2157667. The reversal of 2157647 is 7467512.

2157647 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2157647 - 2⁸ = 2157391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2468 + ... + 3225.

It is an arithmetic number, because the mean of its divisors is an integer number (540930).

2^2157647 is an apocalyptic number.

2157647 is a deficient number, since it is larger than the sum of its proper divisors (6073).

2157647 is an equidigital number, since it uses as much as digits as its factorization.

2157647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6072.

The product of its digits is 11760, while the sum is 32.

The square root of 2157647 is about 1468.8931206865. The cubic root of 2157647 is about 129.2191255989.

The spelling of 2157647 in words is "two million, one hundred fifty-seven thousand, six hundred forty-seven".