747231721 has 4 divisors (see below), whose sum is σ = 748243600. Its totient is φ = 746219844.

The previous prime is 747231701. The next prime is 747231743. The reversal of 747231721 is 127132747.

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.

It is a cyclic number.

It is not a de Polignac number, because 747231721 - 2⁵ = 747231689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (747231701) 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, 504831 + ... + 506308.

It is an arithmetic number, because the mean of its divisors is an integer number (187060900).

Almost surely, 2^747231721 is an apocalyptic number.

It is an amenable number.

747231721 is a deficient number, since it is larger than the sum of its proper divisors (1011879).

747231721 is a wasteful number, since it uses less digits than its factorization.

747231721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1011878.

The product of its digits is 16464, while the sum is 34.

The square root of 747231721 is about 27335.5395227532. The cubic root of 747231721 is about 907.4410745257.

It can be divided in two parts, 7472 and 31721, that added together give a palindrome (39193).

The spelling of 747231721 in words is "seven hundred forty-seven million, two hundred thirty-one thousand, seven hundred twenty-one".