216057 has 4 divisors (see below), whose sum is σ = 288080. Its totient is φ = 144036.

The previous prime is 216037. The next prime is 216061. The reversal of 216057 is 750612.

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 not a de Polignac number, because 216057 - 2⁸ = 215801 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216037) 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, 36007 + ... + 36012.

It is an arithmetic number, because the mean of its divisors is an integer number (72020).

216057 is a Friedman number, since it can be written as 60^(2+1)+57, using all its digits and the basic arithmetic operations.

2²¹⁶⁰⁵⁷ is an apocalyptic number.

It is an amenable number.

216057 is a deficient number, since it is larger than the sum of its proper divisors (72023).

216057 is an equidigital number, since it uses as much as digits as its factorization.

216057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72022.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 216057 is about 464.8193197362. The cubic root of 216057 is about 60.0052773136.

Adding to 216057 its reverse (750612), we get a palindrome (966669).

It can be divided in two parts, 21605 and 7, that added together give a palindrome (21612).

The spelling of 216057 in words is "two hundred sixteen thousand, fifty-seven".