655633440 has 672 divisors, whose sum is σ = 2935046016. Its totient is φ = 134369280.

The previous prime is 655633439. The next prime is 655633457. The reversal of 655633440 is 44336556.

655633440 is a `hidden beast` number, since 65 + 563 + 34 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 655633395 and 655633404.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 8981244 + ... + 8981316.

It is an arithmetic number, because the mean of its divisors is an integer number (4367628).

Almost surely, 2^655633440 is an apocalyptic number.

655633440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 655633440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1467523008).

655633440 is an abundant number, since it is smaller than the sum of its proper divisors (2279412576).

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

655633440 is a wasteful number, since it uses less digits than its factorization.

655633440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

The square root of 655633440 is about 25605.3400680405. The cubic root of 655633440 is about 868.7344262343.

Adding to 655633440 its reverse (44336556), we get a palindrome (699969996).

The spelling of 655633440 in words is "six hundred fifty-five million, six hundred thirty-three thousand, four hundred forty".