645184540 has 288 divisors, whose sum is σ = 1906619904. Its totient is φ = 177914880.

The previous prime is 645184531. The next prime is 645184559. The reversal of 645184540 is 45481546.

645184540 = T₄₄₂₃ + T₄₄₂₄ + ... + T₄₄₈₇.

645184540 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 (37).

It is a self number, because there is not a number n which added to its sum of digits gives 645184540.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9629587 + ... + 9629653.

It is an arithmetic number, because the mean of its divisors is an integer number (6620208).

Almost surely, 2^645184540 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645184540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (953309952).

645184540 is an abundant number, since it is smaller than the sum of its proper divisors (1261435364).

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

645184540 is a wasteful number, since it uses less digits than its factorization.

645184540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 37.

The square root of 645184540 is about 25400.4830662726. The cubic root of 645184540 is about 864.0946523390.

The spelling of 645184540 in words is "six hundred forty-five million, one hundred eighty-four thousand, five hundred forty".