656621012 has 6 divisors (see below), whose sum is σ = 1149086778. Its totient is φ = 328310504.

The previous prime is 656621011. The next prime is 656621023. The reversal of 656621012 is 210126656.

It can be written as a sum of positive squares in only one way, i.e., 653109136 + 3511876 = 25556^2 + 1874^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656621011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82077623 + ... + 82077630.

It is an arithmetic number, because the mean of its divisors is an integer number (191514463).

Almost surely, 2^656621012 is an apocalyptic number.

It is an amenable number.

656621012 is a deficient number, since it is larger than the sum of its proper divisors (492465766).

656621012 is a wasteful number, since it uses less digits than its factorization.

656621012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164155257 (or 164155255 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 656621012 is about 25624.6173044594. The cubic root of 656621012 is about 869.1703951440.

Adding to 656621012 its reverse (210126656), we get a palindrome (866747668).

The spelling of 656621012 in words is "six hundred fifty-six million, six hundred twenty-one thousand, twelve".