216940005 has 64 divisors (see below), whose sum is σ = 411264000. Its totient is φ = 108184896.

The previous prime is 216939949. The next prime is 216940007. The reversal of 216940005 is 500049612.

It is not a de Polignac number, because 216940005 - 2⁹ = 216939493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216940007) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 212386 + ... + 213404.

It is an arithmetic number, because the mean of its divisors is an integer number (6426000).

Almost surely, 2^216940005 is an apocalyptic number.

It is an amenable number.

216940005 is a deficient number, since it is larger than the sum of its proper divisors (194323995).

216940005 is a wasteful number, since it uses less digits than its factorization.

216940005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1135 (or 1129 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 216940005 is about 14728.8833588972. The cubic root of 216940005 is about 600.8691154560.

Adding to 216940005 its reverse (500049612), we get a palindrome (716989617).

The spelling of 216940005 in words is "two hundred sixteen million, nine hundred forty thousand, five".