656740 has 24 divisors (see below), whose sum is σ = 1576512. Its totient is φ = 225120.

The previous prime is 656737. The next prime is 656741. The reversal of 656740 is 47656.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 656699 and 656708.

It is not an unprimeable number, because it can be changed into a prime (656741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2206 + ... + 2485.

It is an arithmetic number, because the mean of its divisors is an integer number (65688).

2⁶⁵⁶⁷⁴⁰ is an apocalyptic number.

It is an amenable number.

656740 is an abundant number, since it is smaller than the sum of its proper divisors (919772).

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

656740 is a wasteful number, since it uses less digits than its factorization.

656740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4707 (or 4705 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 656740 is about 810.3949654335. The cubic root of 656740 is about 86.9222893515.

The spelling of 656740 in words is "six hundred fifty-six thousand, seven hundred forty".