655402240 has 72 divisors (see below), whose sum is σ = 1599679368. Its totient is φ = 257187840.

The previous prime is 655402213. The next prime is 655402243. The reversal of 655402240 is 42204556.

It can be written as a sum of positive squares in 4 ways, for example, as 1679616 + 653722624 = 1296^2 + 25568^2 .

It is a junction number, because it is equal to n+sod(n) for n = 655402199 and 655402208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655402243) 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, 63010 + ... + 72670.

It is an arithmetic number, because the mean of its divisors is an integer number (22217769).

Almost surely, 2^655402240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 655402240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799839684).

655402240 is an abundant number, since it is smaller than the sum of its proper divisors (944277128).

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

655402240 is an equidigital number, since it uses as much as digits as its factorization.

655402240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9735 (or 9721 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 28.

The square root of 655402240 is about 25600.8249867070. The cubic root of 655402240 is about 868.6322985306.

Adding to 655402240 its reverse (42204556), we get a palindrome (697606796).

The spelling of 655402240 in words is "six hundred fifty-five million, four hundred two thousand, two hundred forty".