216409057 has 4 divisors (see below), whose sum is σ = 216454336. Its totient is φ = 216363780.

The previous prime is 216409033. The next prime is 216409079. The reversal of 216409057 is 750904612.

216409057 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216409057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216409027) 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, 14493 + ... + 25354.

It is an arithmetic number, because the mean of its divisors is an integer number (54113584).

Almost surely, 2^216409057 is an apocalyptic number.

It is an amenable number.

216409057 is a deficient number, since it is larger than the sum of its proper divisors (45279).

216409057 is an equidigital number, since it uses as much as digits as its factorization.

216409057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45278.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 216409057 is about 14710.8482760173. The cubic root of 216409057 is about 600.3785176386.

The spelling of 216409057 in words is "two hundred sixteen million, four hundred nine thousand, fifty-seven".