216971503205 has 32 divisors (see below), whose sum is σ = 263993901408. Its totient is φ = 171174016000.

The previous prime is 216971503153. The next prime is 216971503213. The reversal of 216971503205 is 502305179612.

It is a Cunningham number, because it is equal to 465802²+1.

It can be written as a sum of positive squares in 16 ways, for example, as 8508033121 + 208463470084 = 92239^2 + 456578^2 .

It is not a de Polignac number, because 216971503205 - 2³² = 212676535909 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 264276695 + ... + 264277515.

It is an arithmetic number, because the mean of its divisors is an integer number (8249809419).

Almost surely, 2^216971503205 is an apocalyptic number.

It is an amenable number.

216971503205 is a deficient number, since it is larger than the sum of its proper divisors (47022398203).

216971503205 is a wasteful number, since it uses less digits than its factorization.

216971503205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2377.

The product of its (nonzero) digits is 113400, while the sum is 41.

The spelling of 216971503205 in words is "two hundred sixteen billion, nine hundred seventy-one million, five hundred three thousand, two hundred five".