216435021 has 16 divisors (see below), whose sum is σ = 317936448. Its totient is φ = 129872000.

The previous prime is 216435017. The next prime is 216435031. The reversal of 216435021 is 120534612.

216435021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 216435021 - 2² = 216435017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216434982 and 216435000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216435031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29136 + ... + 35801.

It is an arithmetic number, because the mean of its divisors is an integer number (19871028).

Almost surely, 2^216435021 is an apocalyptic number.

It is an amenable number.

216435021 is a deficient number, since it is larger than the sum of its proper divisors (101501427).

216435021 is a wasteful number, since it uses less digits than its factorization.

216435021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65052.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 216435021 is about 14711.7307275521. The cubic root of 216435021 is about 600.4025271150.

Adding to 216435021 its reverse (120534612), we get a palindrome (336969633).

The spelling of 216435021 in words is "two hundred sixteen million, four hundred thirty-five thousand, twenty-one".