665855351650 has 12 divisors (see below), whose sum is σ = 1238490954162. Its totient is φ = 266342140640.

The previous prime is 665855351563. The next prime is 665855351653. The reversal of 665855351650 is 56153558566.

It can be written as a sum of positive squares in 3 ways, for example, as 616506062041 + 49349289609 = 785179^2 + 222147^2 .

It is a junction number, because it is equal to n+sod(n) for n = 665855351591 and 665855351600.

It is not an unprimeable number, because it can be changed into a prime (665855351653) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6658553467 + ... + 6658553566.

Almost surely, 2^665855351650 is an apocalyptic number.

665855351650 is a deficient number, since it is larger than the sum of its proper divisors (572635602512).

665855351650 is a wasteful number, since it uses less digits than its factorization.

665855351650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13317107045 (or 13317107040 counting only the distinct ones).

The product of its (nonzero) digits is 16200000, while the sum is 55.

The spelling of 665855351650 in words is "six hundred sixty-five billion, eight hundred fifty-five million, three hundred fifty-one thousand, six hundred fifty".