215804 has 6 divisors (see below), whose sum is σ = 377664. Its totient is φ = 107900.

The previous prime is 215801. The next prime is 215827. The reversal of 215804 is 408512.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 215804.

It is not an unprimeable number, because it can be changed into a prime (215801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26972 + ... + 26979.

It is an arithmetic number, because the mean of its divisors is an integer number (62944).

2²¹⁵⁸⁰⁴ is an apocalyptic number.

It is an amenable number.

215804 is a deficient number, since it is larger than the sum of its proper divisors (161860).

215804 is a wasteful number, since it uses less digits than its factorization.

215804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53955 (or 53953 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 215804 is about 464.5470912620. The cubic root of 215804 is about 59.9818463598.

It can be divided in two parts, 21580 and 4, that multiplied together give a triangular number (86320 = T₄₁₅).

The spelling of 215804 in words is "two hundred fifteen thousand, eight hundred four".