20856929803 has 4 divisors (see below), whose sum is σ = 20877358768. Its totient is φ = 20836500840.

The previous prime is 20856929789. The next prime is 20856929809. The reversal of 20856929803 is 30892965802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20856929803 - 2²¹ = 20854832651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20856929809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10212951 + ... + 10214992.

It is an arithmetic number, because the mean of its divisors is an integer number (5219339692).

Almost surely, 2^20856929803 is an apocalyptic number.

20856929803 is a deficient number, since it is larger than the sum of its proper divisors (20428965).

20856929803 is a wasteful number, since it uses less digits than its factorization.

20856929803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20428964.

The product of its (nonzero) digits is 1866240, while the sum is 52.

The spelling of 20856929803 in words is "twenty billion, eight hundred fifty-six million, nine hundred twenty-nine thousand, eight hundred three".