656427280 has 80 divisors (see below), whose sum is σ = 1555172784. Its totient is φ = 257638400.

The previous prime is 656427271. The next prime is 656427281. The reversal of 656427280 is 82724656.

It can be written as a sum of positive squares in 8 ways, for example, as 66520336 + 589906944 = 8156^2 + 24288^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (656427281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1106664 + ... + 1107256.

Almost surely, 2^656427280 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656427280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (777586392).

656427280 is an abundant number, since it is smaller than the sum of its proper divisors (898745504).

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

656427280 is a wasteful number, since it uses less digits than its factorization.

656427280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844 (or 838 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 40.

The square root of 656427280 is about 25620.8368325471. The cubic root of 656427280 is about 869.0849056054.

The spelling of 656427280 in words is "six hundred fifty-six million, four hundred twenty-seven thousand, two hundred eighty".