21685945803 has 16 divisors (see below), whose sum is σ = 29618768256. Its totient is φ = 14105931840.

The previous prime is 21685945781. The next prime is 21685945819. The reversal of 21685945803 is 30854958612.

It is not a de Polignac number, because 21685945803 - 2⁹ = 21685945291 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21685945703) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31168 + ... + 210578.

It is an arithmetic number, because the mean of its divisors is an integer number (1851173016).

Almost surely, 2^21685945803 is an apocalyptic number.

21685945803 is a deficient number, since it is larger than the sum of its proper divisors (7932822453).

21685945803 is a wasteful number, since it uses less digits than its factorization.

21685945803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180394.

The product of its (nonzero) digits is 2073600, while the sum is 51.

The spelling of 21685945803 in words is "twenty-one billion, six hundred eighty-five million, nine hundred forty-five thousand, eight hundred three".