645048 has 72 divisors (see below), whose sum is σ = 1915680. Its totient is φ = 195840.

The previous prime is 645041. The next prime is 645049. The reversal of 645048 is 840546.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645048.

It is not an unprimeable number, because it can be changed into a prime (645041) by changing a digit.

645048 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 20793 + ... + 20823.

2⁶⁴⁵⁰⁴⁸ is an apocalyptic number.

645048 is a gapful number since it is divisible by the number (68) 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 645048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (957840).

645048 is an abundant number, since it is smaller than the sum of its proper divisors (1270632).

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

645048 is a wasteful number, since it uses less digits than its factorization.

645048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 645048 is about 803.1488031492. The cubic root of 645048 is about 86.4033692102.

It can be divided in two parts, 6 and 45048, that added together give a palindrome (45054).

The spelling of 645048 in words is "six hundred forty-five thousand, forty-eight".