7231312721 has 4 divisors (see below), whose sum is σ = 7407686244. Its totient is φ = 7054939200.

The previous prime is 7231312703. The next prime is 7231312783. The reversal of 7231312721 is 1272131327.

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 402604225 + 6828708496 = 20065^2 + 82636^2 .

It is a cyclic number.

It is not a de Polignac number, because 7231312721 - 2¹⁸ = 7231050577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7231314721) 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, 88186700 + ... + 88186781.

It is an arithmetic number, because the mean of its divisors is an integer number (1851921561).

Almost surely, 2^7231312721 is an apocalyptic number.

It is an amenable number.

7231312721 is a deficient number, since it is larger than the sum of its proper divisors (176373523).

7231312721 is a wasteful number, since it uses less digits than its factorization.

7231312721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176373522.

The product of its digits is 3528, while the sum is 29.

The square root of 7231312721 is about 85037.1255452582. The cubic root of 7231312721 is about 1933.7739894849.

The spelling of 7231312721 in words is "seven billion, two hundred thirty-one million, three hundred twelve thousand, seven hundred twenty-one".