2153721 has 8 divisors (see below), whose sum is σ = 2879104. Its totient is φ = 1432080.

The previous prime is 2153717. The next prime is 2153729. The reversal of 2153721 is 1273512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2153721 - 2² = 2153717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2153729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 960 + ... + 2286.

It is an arithmetic number, because the mean of its divisors is an integer number (359888).

2^2153721 is an apocalyptic number.

It is an amenable number.

2153721 is a deficient number, since it is larger than the sum of its proper divisors (725383).

2153721 is a wasteful number, since it uses less digits than its factorization.

2153721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1871.

The product of its digits is 420, while the sum is 21.

The square root of 2153721 is about 1467.5561318055. The cubic root of 2153721 is about 129.1407033953.

The spelling of 2153721 in words is "two million, one hundred fifty-three thousand, seven hundred twenty-one".