20781873508 has 24 divisors (see below), whose sum is σ = 39896146080. Its totient is φ = 9393529920.

The previous prime is 20781873481. The next prime is 20781873557. The reversal of 20781873508 is 80537818702.

It is a happy number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1311441 + ... + 1327192.

It is an arithmetic number, because the mean of its divisors is an integer number (1662339420).

Almost surely, 2^20781873508 is an apocalyptic number.

It is an amenable number.

20781873508 is a deficient number, since it is larger than the sum of its proper divisors (19114272572).

20781873508 is a wasteful number, since it uses less digits than its factorization.

20781873508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2638827 (or 2638825 counting only the distinct ones).

The product of its (nonzero) digits is 752640, while the sum is 49.

The spelling of 20781873508 in words is "twenty billion, seven hundred eighty-one million, eight hundred seventy-three thousand, five hundred eight".