1660861440 has 528 divisors, whose sum is σ = 6948664320. Its totient is φ = 358318080.

The previous prime is 1660861373. The next prime is 1660861511. The reversal of 1660861440 is 441680661.

1660861440 is a `hidden beast` number, since 1 + 6 + 608 + 6 + 1 + 4 + 40 = 666.

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 = 1660861395 and 1660861404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6128505 + ... + 6128775.

Almost surely, 2^1660861440 is an apocalyptic number.

1660861440 is a gapful number since it is divisible by the number (10) 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 1660861440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3474332160).

1660861440 is an abundant number, since it is smaller than the sum of its proper divisors (5287802880).

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

1660861440 is a wasteful number, since it uses less digits than its factorization.

1660861440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1660861440 is about 40753.6678103947. The cubic root of 1660861440 is about 1184.2529286774.

The spelling of 1660861440 in words is "one billion, six hundred sixty million, eight hundred sixty-one thousand, four hundred forty".