6440725 has 12 divisors (see below), whose sum is σ = 8027140. Its totient is φ = 5126400.

The previous prime is 6440723. The next prime is 6440737. The reversal of 6440725 is 5270446.

It can be written as a sum of positive squares in 6 ways, for example, as 4356 + 6436369 = 66^2 + 2537^2 .

It is not a de Polignac number, because 6440725 - 2¹ = 6440723 is a prime.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 6440693 and 6440702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5491 + ... + 6559.

Almost surely, 2^6440725 is an apocalyptic number.

It is an amenable number.

6440725 is a deficient number, since it is larger than the sum of its proper divisors (1586415).

6440725 is a wasteful number, since it uses less digits than its factorization.

6440725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320 (or 1315 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 6440725 is about 2537.8583490810. The cubic root of 6440725 is about 186.0565307801.

The spelling of 6440725 in words is "six million, four hundred forty thousand, seven hundred twenty-five".