660559440 has 40 divisors (see below), whose sum is σ = 2047735008. Its totient is φ = 176149120.

The previous prime is 660559411. The next prime is 660559447. The reversal of 660559440 is 44955066.

660559440 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×660559440² = 872677547546227200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660559447) 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, 1375926 + ... + 1376405.

Almost surely, 2^660559440 is an apocalyptic number.

660559440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

660559440 is an abundant number, since it is smaller than the sum of its proper divisors (1387175568).

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

660559440 is a wasteful number, since it uses less digits than its factorization.

660559440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2752347 (or 2752341 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 39.

The square root of 660559440 is about 25701.3509372562. The cubic root of 660559440 is about 870.9047003214.

The spelling of 660559440 in words is "six hundred sixty million, five hundred fifty-nine thousand, four hundred forty".