63967472781 has 4 divisors (see below), whose sum is σ = 85289963712. Its totient is φ = 42644981852.

The previous prime is 63967472747. The next prime is 63967472809. The reversal of 63967472781 is 18727476936.

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 63967472781 - 2²⁷ = 63833255053 is a prime.

It is a super-2 number, since 2×63967472781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63967472731) 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, 10661245461 + ... + 10661245466.

It is an arithmetic number, because the mean of its divisors is an integer number (21322490928).

Almost surely, 2^63967472781 is an apocalyptic number.

It is an amenable number.

63967472781 is a deficient number, since it is larger than the sum of its proper divisors (21322490931).

63967472781 is a wasteful number, since it uses less digits than its factorization.

63967472781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21322490930.

The product of its digits is 21337344, while the sum is 60.

The spelling of 63967472781 in words is "sixty-three billion, nine hundred sixty-seven million, four hundred seventy-two thousand, seven hundred eighty-one".