2157549 has 4 divisors (see below), whose sum is σ = 2876736. Its totient is φ = 1438364.

The previous prime is 2157539. The next prime is 2157557. The reversal of 2157549 is 9457512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2157549 - 2⁵ = 2157517 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157539) 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 3 ways as a sum of consecutive naturals, for example, 359589 + ... + 359594.

It is an arithmetic number, because the mean of its divisors is an integer number (719184).

2^2157549 is an apocalyptic number.

It is an amenable number.

2157549 is a deficient number, since it is larger than the sum of its proper divisors (719187).

2157549 is an equidigital number, since it uses as much as digits as its factorization.

2157549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719186.

The product of its digits is 12600, while the sum is 33.

The square root of 2157549 is about 1468.8597618561. The cubic root of 2157549 is about 129.2171691983.

Multiplying 2157549 by its sum of digits (33), we get a palindrome (71199117).

The spelling of 2157549 in words is "two million, one hundred fifty-seven thousand, five hundred forty-nine".