63894526681 has 4 divisors (see below), whose sum is σ = 64794449664. Its totient is φ = 62994603700.

The previous prime is 63894526669. The next prime is 63894526763. The reversal of 63894526681 is 18662549836.

63894526681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 63894526681 - 2⁹ = 63894526169 is a prime.

It is a super-2 number, since 2×63894526681² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63894526601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 449961385 + ... + 449961526.

It is an arithmetic number, because the mean of its divisors is an integer number (16198612416).

Almost surely, 2^63894526681 is an apocalyptic number.

It is an amenable number.

63894526681 is a deficient number, since it is larger than the sum of its proper divisors (899922983).

63894526681 is an equidigital number, since it uses as much as digits as its factorization.

63894526681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 899922982.

The product of its digits is 14929920, while the sum is 58.

The spelling of 63894526681 in words is "sixty-three billion, eight hundred ninety-four million, five hundred twenty-six thousand, six hundred eighty-one".