1645666960 has 180 divisors, whose sum is σ = 4586361588. Its totient is φ = 547362816.

The previous prime is 1645666937. The next prime is 1645666987. The reversal of 1645666960 is 696665461.

It can be written as a sum of positive squares in 6 ways, for example, as 133079296 + 1512587664 = 11536^2 + 38892^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 18490596 + ... + 18490684.

Almost surely, 2^1645666960 is an apocalyptic number.

1645666960 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 1645666960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2293180794).

1645666960 is an abundant number, since it is smaller than the sum of its proper divisors (2940694628).

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

1645666960 is an equidigital number, since it uses as much as digits as its factorization.

1645666960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 49.

The square root of 1645666960 is about 40566.8209254805. The cubic root of 1645666960 is about 1180.6304588423.

The spelling of 1645666960 in words is "one billion, six hundred forty-five million, six hundred sixty-six thousand, nine hundred sixty".