645838500 has 384 divisors, whose sum is σ = 2214051840. Its totient is φ = 145152000.

The previous prime is 645838499. The next prime is 645838547. The reversal of 645838500 is 5838546.

It is a happy number.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 15019479 + ... + 15019521.

It is an arithmetic number, because the mean of its divisors is an integer number (5765760).

Almost surely, 2^645838500 is an apocalyptic number.

645838500 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 645838500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1107025920).

645838500 is an abundant number, since it is smaller than the sum of its proper divisors (1568213340).

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

645838500 is a wasteful number, since it uses less digits than its factorization.

645838500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 39.

The square root of 645838500 is about 25413.3527894294. The cubic root of 645838500 is about 864.3865029585.

The spelling of 645838500 in words is "six hundred forty-five million, eight hundred thirty-eight thousand, five hundred".