7142721 has 4 divisors (see below), whose sum is σ = 9523632. Its totient is φ = 4761812.

The previous prime is 7142713. The next prime is 7142743. The reversal of 7142721 is 1272417.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1272417 = 3 ⋅424139.

It is a cyclic number.

It is not a de Polignac number, because 7142721 - 2³ = 7142713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7142691 and 7142700.

It is not an unprimeable number, because it can be changed into a prime (7142791) 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, 1190451 + ... + 1190456.

It is an arithmetic number, because the mean of its divisors is an integer number (2380908).

Almost surely, 2^7142721 is an apocalyptic number.

It is an amenable number.

7142721 is a deficient number, since it is larger than the sum of its proper divisors (2380911).

7142721 is a wasteful number, since it uses less digits than its factorization.

7142721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2380910.

The product of its digits is 784, while the sum is 24.

The square root of 7142721 is about 2672.5869490065. The cubic root of 7142721 is about 192.5844549866.

The spelling of 7142721 in words is "seven million, one hundred forty-two thousand, seven hundred twenty-one".