20688748787 has 12 divisors (see below), whose sum is σ = 24228032400. Its totient is φ = 17614192176.

The previous prime is 20688748777. The next prime is 20688748793. The reversal of 20688748787 is 78784788602.

It is not a de Polignac number, because 20688748787 - 2¹⁶ = 20688683251 is a prime.

It is a Smith number, since the sum of its digits (65) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20688748777) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1409543 + ... + 1424144.

It is an arithmetic number, because the mean of its divisors is an integer number (2019002700).

Almost surely, 2^20688748787 is an apocalyptic number.

20688748787 is a deficient number, since it is larger than the sum of its proper divisors (3539283613).

20688748787 is a wasteful number, since it uses less digits than its factorization.

20688748787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2833850 (or 2833843 counting only the distinct ones).

The product of its (nonzero) digits is 67436544, while the sum is 65.

The spelling of 20688748787 in words is "twenty billion, six hundred eighty-eight million, seven hundred forty-eight thousand, seven hundred eighty-seven".