263642551556641 has 32 divisors (see below), whose sum is σ = 286983293829120. Its totient is φ = 241277196614400.

The previous prime is 263642551556633. The next prime is 263642551556653. The reversal of 263642551556641 is 146655155246362.

It is a cyclic number.

It is not a de Polignac number, because 263642551556641 - 2³ = 263642551556633 is a prime.

It is a super-2 number, since 2×263642551556641² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 263642551556641.

It is not an unprimeable number, because it can be changed into a prime (263642551556621) 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 31 ways as a sum of consecutive naturals, for example, 5261146176 + ... + 5261196286.

It is an arithmetic number, because the mean of its divisors is an integer number (8968227932160).

Almost surely, 2^{263642551556641} is an apocalyptic number.

It is an amenable number.

263642551556641 is a deficient number, since it is larger than the sum of its proper divisors (23340742272479).

263642551556641 is a wasteful number, since it uses less digits than its factorization.

263642551556641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65965.

The product of its digits is 155520000, while the sum is 61.

The spelling of 263642551556641 in words is "two hundred sixty-three trillion, six hundred forty-two billion, five hundred fifty-one million, five hundred fifty-six thousand, six hundred forty-one".