2149821 has 16 divisors (see below), whose sum is σ = 3227520. Its totient is φ = 1431756.

The previous prime is 2149813. The next prime is 2149853. The reversal of 2149821 is 1289412.

It is not a de Polignac number, because 2149821 - 2³ = 2149813 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 (2149421) 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, 1696 + ... + 2678.

It is an arithmetic number, because the mean of its divisors is an integer number (201720).

2^2149821 is an apocalyptic number.

It is an amenable number.

2149821 is a deficient number, since it is larger than the sum of its proper divisors (1077699).

2149821 is an frugal number, since it uses more digits than its factorization.

2149821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004 (or 986 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 2149821 is about 1466.2267900976. The cubic root of 2149821 is about 129.0627061284.

The spelling of 2149821 in words is "two million, one hundred forty-nine thousand, eight hundred twenty-one".