665551110501 has 24 divisors (see below), whose sum is σ = 975612718080. Its totient is φ = 437162425056.

The previous prime is 665551110473. The next prime is 665551110503. The reversal of 665551110501 is 105011155566.

It is a happy number.

It is not a de Polignac number, because 665551110501 - 2⁶ = 665551110437 is a prime.

It is a super-2 number, since 2×665551110501² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665551110503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1639621 + ... + 2004858.

It is an arithmetic number, because the mean of its divisors is an integer number (40650529920).

Almost surely, 2^665551110501 is an apocalyptic number.

It is an amenable number.

665551110501 is a deficient number, since it is larger than the sum of its proper divisors (310061607579).

665551110501 is a wasteful number, since it uses less digits than its factorization.

665551110501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3644785 (or 3644782 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 36.

The spelling of 665551110501 in words is "six hundred sixty-five billion, five hundred fifty-one million, one hundred ten thousand, five hundred one".