1645997760 has 560 divisors, whose sum is σ = 6691652352. Its totient is φ = 380160000.

The previous prime is 1645997719. The next prime is 1645997789. The reversal of 1645997760 is 677995461.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 1645997697 and 1645997706.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 6557635 + ... + 6557885.

Almost surely, 2^1645997760 is an apocalyptic number.

1645997760 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 1645997760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3345826176).

1645997760 is an abundant number, since it is smaller than the sum of its proper divisors (5045654592).

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

1645997760 is a wasteful number, since it uses less digits than its factorization.

1645997760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314 (or 295 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 54.

The square root of 1645997760 is about 40570.8979442161. The cubic root of 1645997760 is about 1180.7095607909.

The spelling of 1645997760 in words is "one billion, six hundred forty-five million, nine hundred ninety-seven thousand, seven hundred sixty".