216202405 has 4 divisors (see below), whose sum is σ = 259442892. Its totient is φ = 172961920.

The previous prime is 216202403. The next prime is 216202411. The reversal of 216202405 is 504202612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 104223681 + 111978724 = 10209^2 + 10582^2 .

It is not a de Polignac number, because 216202405 - 2¹ = 216202403 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216202403) 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, 21620236 + ... + 21620245.

It is an arithmetic number, because the mean of its divisors is an integer number (64860723).

Almost surely, 2^216202405 is an apocalyptic number.

It is an amenable number.

216202405 is a deficient number, since it is larger than the sum of its proper divisors (43240487).

216202405 is an equidigital number, since it uses as much as digits as its factorization.

216202405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43240486.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 216202405 is about 14703.8228022511. The cubic root of 216202405 is about 600.1873535287.

It can be divided in two parts, 21620 and 2405, that added together give a square (24025 = 155²).

The spelling of 216202405 in words is "two hundred sixteen million, two hundred two thousand, four hundred five".