216121051 has 4 divisors (see below), whose sum is σ = 228834072. Its totient is φ = 203408032.

The previous prime is 216121043. The next prime is 216121069. The reversal of 216121051 is 150121612.

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

It is a cyclic number.

It is not a de Polignac number, because 216121051 - 2³ = 216121043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216128051) 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, 6356485 + ... + 6356518.

It is an arithmetic number, because the mean of its divisors is an integer number (57208518).

Almost surely, 2^216121051 is an apocalyptic number.

216121051 is a deficient number, since it is larger than the sum of its proper divisors (12713021).

216121051 is a wasteful number, since it uses less digits than its factorization.

216121051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12713020.

The product of its (nonzero) digits is 120, while the sum is 19.

The square root of 216121051 is about 14701.0561185243. The cubic root of 216121051 is about 600.1120633276.

Adding to 216121051 its reverse (150121612), we get a palindrome (366242663).

The spelling of 216121051 in words is "two hundred sixteen million, one hundred twenty-one thousand, fifty-one".