721474549 has 4 divisors (see below), whose sum is σ = 731357836. Its totient is φ = 711591264.

The previous prime is 721474541. The next prime is 721474601. The reversal of 721474549 is 945474127.

721474549 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 429235524 + 292239025 = 20718^2 + 17095^2 .

It is a cyclic number.

It is not a de Polignac number, because 721474549 - 2³ = 721474541 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721474541) 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, 4941534 + ... + 4941679.

It is an arithmetic number, because the mean of its divisors is an integer number (182839459).

Almost surely, 2^721474549 is an apocalyptic number.

It is an amenable number.

721474549 is a deficient number, since it is larger than the sum of its proper divisors (9883287).

721474549 is an equidigital number, since it uses as much as digits as its factorization.

721474549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9883286.

The product of its digits is 282240, while the sum is 43.

The square root of 721474549 is about 26860.2782748057. The cubic root of 721474549 is about 896.8923886587.

The spelling of 721474549 in words is "seven hundred twenty-one million, four hundred seventy-four thousand, five hundred forty-nine".