216522406 has 4 divisors (see below), whose sum is σ = 324783612. Its totient is φ = 108261202.

The previous prime is 216522403. The next prime is 216522407. The reversal of 216522406 is 604225612.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216522401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54130600 + ... + 54130603.

It is an arithmetic number, because the mean of its divisors is an integer number (81195903).

Almost surely, 2^216522406 is an apocalyptic number.

216522406 is a deficient number, since it is larger than the sum of its proper divisors (108261206).

216522406 is a wasteful number, since it uses less digits than its factorization.

216522406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108261205.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 216522406 is about 14714.7003367381. The cubic root of 216522406 is about 600.4833198246.

The spelling of 216522406 in words is "two hundred sixteen million, five hundred twenty-two thousand, four hundred six".