730172521 has 8 divisors (see below), whose sum is σ = 786549960. Its totient is φ = 673825152.

The previous prime is 730172519. The next prime is 730172533. The reversal of 730172521 is 125271037.

It can be written as a sum of positive squares in 4 ways, for example, as 144000000 + 586172521 = 12000^2 + 24211^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 730172521 - 2¹ = 730172519 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 730172521.

It is not an unprimeable number, because it can be changed into a prime (730172561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87165 + ... + 95173.

It is an arithmetic number, because the mean of its divisors is an integer number (98318745).

Almost surely, 2^730172521 is an apocalyptic number.

It is an amenable number.

730172521 is a deficient number, since it is larger than the sum of its proper divisors (56377439).

730172521 is a wasteful number, since it uses less digits than its factorization.

730172521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15035.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 730172521 is about 27021.7046279468. The cubic root of 730172521 is about 900.4822604670.

The spelling of 730172521 in words is "seven hundred thirty million, one hundred seventy-two thousand, five hundred twenty-one".