20688748785 has 32 divisors (see below), whose sum is σ = 38715792000. Its totient is φ = 10453261248.

The previous prime is 20688748777. The next prime is 20688748793. The reversal of 20688748785 is 58784788602.

It is an interprime number because it is at equal distance from previous prime (20688748777) and next prime (20688748793).

It is not a de Polignac number, because 20688748785 - 2³ = 20688748777 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4030330 + ... + 4035459.

It is an arithmetic number, because the mean of its divisors is an integer number (1209868500).

Almost surely, 2^20688748785 is an apocalyptic number.

It is an amenable number.

20688748785 is a deficient number, since it is larger than the sum of its proper divisors (18027043215).

20688748785 is a wasteful number, since it uses less digits than its factorization.

20688748785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8065822 (or 8065816 counting only the distinct ones).

The product of its (nonzero) digits is 48168960, while the sum is 63.

The spelling of 20688748785 in words is "twenty billion, six hundred eighty-eight million, seven hundred forty-eight thousand, seven hundred eighty-five".