2142721 has 8 divisors (see below), whose sum is σ = 2499200. Its totient is φ = 1836324.

The previous prime is 2142719. The next prime is 2142739. The reversal of 2142721 is 1272412.

It is a happy number.

It is not a de Polignac number, because 2142721 - 2¹ = 2142719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2142761) 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, 2781 + ... + 3466.

It is an arithmetic number, because the mean of its divisors is an integer number (312400).

2^2142721 is an apocalyptic number.

It is an amenable number.

2142721 is a deficient number, since it is larger than the sum of its proper divisors (356479).

2142721 is an frugal number, since it uses more digits than its factorization.

2142721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6268 (or 6254 counting only the distinct ones).

The product of its digits is 224, while the sum is 19.

The square root of 2142721 is about 1463.8036070457. The cubic root of 2142721 is about 128.9204685742.

The spelling of 2142721 in words is "two million, one hundred forty-two thousand, seven hundred twenty-one".