2157543 has 16 divisors (see below), whose sum is σ = 3276000. Its totient is φ = 1402560.

The previous prime is 2157539. The next prime is 2157557. The reversal of 2157543 is 3457512.

It is a happy number.

It is not a de Polignac number, because 2157543 - 2² = 2157539 is a prime.

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 (2157503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133 + ... + 2081.

It is an arithmetic number, because the mean of its divisors is an integer number (204750).

2^2157543 is an apocalyptic number.

2157543 is a deficient number, since it is larger than the sum of its proper divisors (1118457).

2157543 is a wasteful number, since it uses less digits than its factorization.

2157543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1999 (or 1993 counting only the distinct ones).

The product of its digits is 4200, while the sum is 27.

The square root of 2157543 is about 1468.8577194541. The cubic root of 2157543 is about 129.2170494167.

The spelling of 2157543 in words is "two million, one hundred fifty-seven thousand, five hundred forty-three".