6497640 has 48 divisors (see below), whose sum is σ = 21118500. Its totient is φ = 1732608.

The previous prime is 6497591. The next prime is 6497683. The reversal of 6497640 is 467946.

6497640 is a `hidden beast` number, since 6 + 4 + 9 + 7 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6380676 + 116964 = 2526^2 + 342^2 .

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 = 6497595 and 6497604.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8665 + ... + 9384.

Almost surely, 2^6497640 is an apocalyptic number.

6497640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6497640 is an abundant number, since it is smaller than the sum of its proper divisors (14620860).

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

6497640 is a wasteful number, since it uses less digits than its factorization.

6497640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18066 (or 18059 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 6497640 is about 2549.0468806987. The cubic root of 6497640 is about 186.6029686290.

The spelling of 6497640 in words is "six million, four hundred ninety-seven thousand, six hundred forty".