6975721 has 4 divisors (see below), whose sum is σ = 7164292. Its totient is φ = 6787152.

The previous prime is 6975719. The next prime is 6975743. The reversal of 6975721 is 1275796.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5953600 + 1022121 = 2440^2 + 1011^2 .

It is a cyclic number.

It is not a de Polignac number, because 6975721 - 2¹ = 6975719 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 188533 = 6975721 / (6 + 9 + 7 + 5 + 7 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6975791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94230 + ... + 94303.

It is an arithmetic number, because the mean of its divisors is an integer number (1791073).

Almost surely, 2^6975721 is an apocalyptic number.

It is an amenable number.

6975721 is a deficient number, since it is larger than the sum of its proper divisors (188571).

6975721 is a wasteful number, since it uses less digits than its factorization.

6975721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188570.

The product of its digits is 26460, while the sum is 37.

The square root of 6975721 is about 2641.1590258824. The cubic root of 6975721 is about 191.0716999160.

The spelling of 6975721 in words is "six million, nine hundred seventy-five thousand, seven hundred twenty-one".