645098040 has 256 divisors, whose sum is σ = 2280960000. Its totient is φ = 161892864.

The previous prime is 645098039. The next prime is 645098057. The reversal of 645098040 is 40890546.

645098040 is a `hidden beast` number, since 645 + 0 + 9 + 8 + 0 + 4 + 0 = 666.

645098040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 = 645097986 and 645098004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1346521 + ... + 1346999.

It is an arithmetic number, because the mean of its divisors is an integer number (8910000).

Almost surely, 2^645098040 is an apocalyptic number.

645098040 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 645098040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1140480000).

645098040 is an abundant number, since it is smaller than the sum of its proper divisors (1635861960).

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

645098040 is a wasteful number, since it uses less digits than its factorization.

645098040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571 (or 561 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 645098040 is about 25398.7802856751. The cubic root of 645098040 is about 864.0560341745.

The spelling of 645098040 in words is "six hundred forty-five million, ninety-eight thousand, forty".