63781219081 has 4 divisors (see below), whose sum is σ = 63782235972. Its totient is φ = 63780202192.

The previous prime is 63781219069. The next prime is 63781219087. The reversal of 63781219081 is 18091218736.

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 7839508681 + 55941710400 = 88541^2 + 236520^2 .

It is a cyclic number.

It is not a de Polignac number, because 63781219081 - 2⁹ = 63781218569 is a prime.

It is a super-2 number, since 2×63781219081² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63781219087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 407710 + ... + 542023.

It is an arithmetic number, because the mean of its divisors is an integer number (15945558993).

Almost surely, 2^63781219081 is an apocalyptic number.

It is an amenable number.

63781219081 is a deficient number, since it is larger than the sum of its proper divisors (1016891).

63781219081 is an equidigital number, since it uses as much as digits as its factorization.

63781219081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016890.

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 63781219081 in words is "sixty-three billion, seven hundred eighty-one million, two hundred nineteen thousand, eighty-one".