216121401 has 6 divisors (see below), whose sum is σ = 312175370. Its totient is φ = 144080928.

The previous prime is 216121387. The next prime is 216121417. The reversal of 216121401 is 104121612.

It can be written as a sum of positive squares in only one way, i.e., 208831401 + 7290000 = 14451^2 + 2700^2 .

It is not a de Polignac number, because 216121401 - 2⁶ = 216121337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216121441) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12006736 + ... + 12006753.

Almost surely, 2^216121401 is an apocalyptic number.

It is an amenable number.

216121401 is a deficient number, since it is larger than the sum of its proper divisors (96053969).

216121401 is a wasteful number, since it uses less digits than its factorization.

216121401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24013495 (or 24013492 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 216121401 is about 14701.0680224261. The cubic root of 216121401 is about 600.1123872805.

The spelling of 216121401 in words is "two hundred sixteen million, one hundred twenty-one thousand, four hundred one".