725221530 has 192 divisors, whose sum is σ = 2233236096. Its totient is φ = 161280000.

The previous prime is 725221463. The next prime is 725221537. The reversal of 725221530 is 35122527.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 725221494 and 725221503.

It is not an unprimeable number, because it can be changed into a prime (725221537) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 689505 + ... + 690555.

It is an arithmetic number, because the mean of its divisors is an integer number (11631438).

Almost surely, 2^725221530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 725221530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1116618048).

725221530 is an abundant number, since it is smaller than the sum of its proper divisors (1508014566).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

725221530 is a wasteful number, since it uses less digits than its factorization.

725221530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133 (or 1130 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 725221530 is about 26929.9374303024. The cubic root of 725221530 is about 898.4423798732.

It can be divided in two parts, 7252 and 21530, that added together give a palindrome (28782).

The spelling of 725221530 in words is "seven hundred twenty-five million, two hundred twenty-one thousand, five hundred thirty".