20563029781 has 12 divisors (see below), whose sum is σ = 23922827040. Its totient is φ = 17623562040.

The previous prime is 20563029769. The next prime is 20563029787. The reversal of 20563029781 is 18792036502.

It is a de Polignac number, because none of the positive numbers 2^k-20563029781 is a prime.

It is a super-2 number, since 2×20563029781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20563029787) 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 11 ways as a sum of consecutive naturals, for example, 628846 + ... + 660736.

It is an arithmetic number, because the mean of its divisors is an integer number (1993568920).

Almost surely, 2^20563029781 is an apocalyptic number.

It is an amenable number.

20563029781 is a deficient number, since it is larger than the sum of its proper divisors (3359797259).

20563029781 is a wasteful number, since it uses less digits than its factorization.

20563029781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45064 (or 45057 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 20563029781 in words is "twenty billion, five hundred sixty-three million, twenty-nine thousand, seven hundred eighty-one".