63505642261 has 4 divisors (see below), whose sum is σ = 63512956332. Its totient is φ = 63498328192.

The previous prime is 63505642253. The next prime is 63505642267. The reversal of 63505642261 is 16224650536.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25209500625 + 38296141636 = 158775^2 + 195694^2 .

It is a cyclic number.

It is not a de Polignac number, because 63505642261 - 2³ = 63505642253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63505642267) 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 3 ways as a sum of consecutive naturals, for example, 3643996 + ... + 3661381.

It is an arithmetic number, because the mean of its divisors is an integer number (15878239083).

Almost surely, 2^63505642261 is an apocalyptic number.

It is an amenable number.

63505642261 is a deficient number, since it is larger than the sum of its proper divisors (7314071).

63505642261 is an equidigital number, since it uses as much as digits as its factorization.

63505642261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7314070.

The product of its (nonzero) digits is 259200, while the sum is 40.

The spelling of 63505642261 in words is "sixty-three billion, five hundred five million, six hundred forty-two thousand, two hundred sixty-one".