203864 has 16 divisors (see below), whose sum is σ = 405000. Its totient is φ = 95872.

The previous prime is 203857. The next prime is 203869. The reversal of 203864 is 468302.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (203869) by changing a digit.

203864 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 614 + ... + 885.

2²⁰³⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

203864 is a deficient number, since it is larger than the sum of its proper divisors (201136).

203864 is a wasteful number, since it uses less digits than its factorization.

203864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1522 (or 1518 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 203864 is about 451.5130119941. The cubic root of 203864 is about 58.8545685600.

Subtracting from 203864 its sum of digits (23), we obtain a triangular number (203841 = T₆₃₈).

The spelling of 203864 in words is "two hundred three thousand, eight hundred sixty-four".