20910887728 has 10 divisors (see below), whose sum is σ = 40514845004. Its totient is φ = 10455443856.

The previous prime is 20910887719. The next prime is 20910887749. The reversal of 20910887728 is 82778801902.

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 as a sum of consecutive naturals, namely, 653465226 + ... + 653465257.

Almost surely, 2^20910887728 is an apocalyptic number.

It is an amenable number.

20910887728 is a deficient number, since it is larger than the sum of its proper divisors (19603957276).

20910887728 is a wasteful number, since it uses less digits than its factorization.

20910887728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1306930491 (or 1306930485 counting only the distinct ones).

The product of its (nonzero) digits is 903168, while the sum is 52.

The spelling of 20910887728 in words is "twenty billion, nine hundred ten million, eight hundred eighty-seven thousand, seven hundred twenty-eight".