20905016885 has 8 divisors (see below), whose sum is σ = 25086799320. Its totient is φ = 16723494144.

The previous prime is 20905016863. The next prime is 20905016903. The reversal of 20905016885 is 58861050902.

It can be written as a sum of positive squares in 4 ways, for example, as 9690630481 + 11214386404 = 98441^2 + 105898^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20905016885 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260201 + ... + 330929.

It is an arithmetic number, because the mean of its divisors is an integer number (3135849915).

Almost surely, 2^20905016885 is an apocalyptic number.

It is an amenable number.

20905016885 is a deficient number, since it is larger than the sum of its proper divisors (4181782435).

20905016885 is an equidigital number, since it uses as much as digits as its factorization.

20905016885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129847.

The product of its (nonzero) digits is 172800, while the sum is 44.

The spelling of 20905016885 in words is "twenty billion, nine hundred five million, sixteen thousand, eight hundred eighty-five".