215641 has 4 divisors (see below), whose sum is σ = 216832. Its totient is φ = 214452.

The previous prime is 215617. The next prime is 215653. The reversal of 215641 is 146512.

215641 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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215641 is a prime.

It is a Duffinian number.

215641 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (215681) 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, 261 + ... + 706.

It is an arithmetic number, because the mean of its divisors is an integer number (54208).

2²¹⁵⁶⁴¹ is an apocalyptic number.

It is an amenable number.

215641 is a deficient number, since it is larger than the sum of its proper divisors (1191).

215641 is an equidigital number, since it uses as much as digits as its factorization.

215641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190.

The product of its digits is 240, while the sum is 19.

The square root of 215641 is about 464.3716184264. The cubic root of 215641 is about 59.9667408265.

It can be divided in two parts, 2156 and 41, that added together give a cube (2197 = 13³).

The spelling of 215641 in words is "two hundred fifteen thousand, six hundred forty-one".