1645897800 has 192 divisors, whose sum is σ = 5399208000. Its totient is φ = 413614080.

The previous prime is 1645897769. The next prime is 1645897801. The reversal of 1645897800 is 87985461.

It is a self number, because there is not a number n which added to its sum of digits gives 1645897800.

It is not an unprimeable number, because it can be changed into a prime (1645897801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4023996 + ... + 4024404.

It is an arithmetic number, because the mean of its divisors is an integer number (28120875).

Almost surely, 2^1645897800 is an apocalyptic number.

1645897800 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 1645897800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2699604000).

1645897800 is an abundant number, since it is smaller than the sum of its proper divisors (3753310200).

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

1645897800 is a wasteful number, since it uses less digits than its factorization.

1645897800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800 (or 791 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 48.

The square root of 1645897800 is about 40569.6660079917. Note that the first 3 decimals coincide. The cubic root of 1645897800 is about 1180.6856591551.

The spelling of 1645897800 in words is "one billion, six hundred forty-five million, eight hundred ninety-seven thousand, eight hundred".