656641040 has 40 divisors (see below), whose sum is σ = 1665482688. Its totient is φ = 238778240.

The previous prime is 656641033. The next prime is 656641043. The reversal of 656641040 is 40146656.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 656640988 and 656641006.

It is not an unprimeable number, because it can be changed into a prime (656641043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 372212 + ... + 373971.

Almost surely, 2^656641040 is an apocalyptic number.

It is an amenable number.

656641040 is an abundant number, since it is smaller than the sum of its proper divisors (1008841648).

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

656641040 is a wasteful number, since it uses less digits than its factorization.

656641040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746207 (or 746201 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 656641040 is about 25625.0080975597. The cubic root of 656641040 is about 869.1792320872.

Adding to 656641040 its reverse (40146656), we get a palindrome (696787696).

The spelling of 656641040 in words is "six hundred fifty-six million, six hundred forty-one thousand, forty".