661264910228 has 12 divisors (see below), whose sum is σ = 1246230023220. Its totient is φ = 305199189312.

The previous prime is 661264910221. The next prime is 661264910263. The reversal of 661264910228 is 822019462166.

It can be written as a sum of positive squares in 2 ways, for example, as 436302523024 + 224962387204 = 660532^2 + 474302^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661264910221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6358316393 + ... + 6358316496.

It is an arithmetic number, because the mean of its divisors is an integer number (103852501935).

Almost surely, 2^661264910228 is an apocalyptic number.

It is an amenable number.

661264910228 is a deficient number, since it is larger than the sum of its proper divisors (584965112992).

661264910228 is a wasteful number, since it uses less digits than its factorization.

661264910228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12716632906 (or 12716632904 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 47.

The spelling of 661264910228 in words is "six hundred sixty-one billion, two hundred sixty-four million, nine hundred ten thousand, two hundred twenty-eight".