660539880 has 768 divisors, whose sum is σ = 3035750400. Its totient is φ = 124001280.

The previous prime is 660539861. The next prime is 660539897. The reversal of 660539880 is 88935066.

660539880 = T₁₅₃ + T₁₅₄ + ... + T₁₅₈₂.

660539880 is a `hidden beast` number, since 6 + 605 + 39 + 8 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 14054017 + ... + 14054063.

It is an arithmetic number, because the mean of its divisors is an integer number (3952800).

Almost surely, 2^660539880 is an apocalyptic number.

660539880 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 660539880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1517875200).

660539880 is an abundant number, since it is smaller than the sum of its proper divisors (2375210520).

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

660539880 is a wasteful number, since it uses less digits than its factorization.

660539880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 660539880 is about 25700.9704096947. The cubic root of 660539880 is about 870.8961040402.

The spelling of 660539880 in words is "six hundred sixty million, five hundred thirty-nine thousand, eight hundred eighty".