645925734 has 48 divisors (see below), whose sum is σ = 1471976064. Its totient is φ = 204422400.

The previous prime is 645925733. The next prime is 645925751. The reversal of 645925734 is 437529546.

645925734 is a `hidden beast` number, since 6 + 4 + 592 + 57 + 3 + 4 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 645925734.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645925733) 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 23 ways as a sum of consecutive naturals, for example, 18654 + ... + 40494.

It is an arithmetic number, because the mean of its divisors is an integer number (30666168).

Almost surely, 2^645925734 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645925734, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (735988032).

645925734 is an abundant number, since it is smaller than the sum of its proper divisors (826050330).

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

645925734 is a wasteful number, since it uses less digits than its factorization.

645925734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21933 (or 21930 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The square root of 645925734 is about 25415.0690339413. The cubic root of 645925734 is about 864.4254190330.

The spelling of 645925734 in words is "six hundred forty-five million, nine hundred twenty-five thousand, seven hundred thirty-four".