213403665 has 16 divisors (see below), whose sum is σ = 341984448. Its totient is φ = 113635776.

The previous prime is 213403661. The next prime is 213403691. The reversal of 213403665 is 566304312.

It is not a de Polignac number, because 213403665 - 2² = 213403661 is a prime.

It is a super-2 number, since 2×213403665² = 91082248470864450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (213403661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1099 + ... + 20688.

It is an arithmetic number, because the mean of its divisors is an integer number (21374028).

Almost surely, 2^213403665 is an apocalyptic number.

It is an amenable number.

213403665 is a deficient number, since it is larger than the sum of its proper divisors (128580783).

213403665 is a wasteful number, since it uses less digits than its factorization.

213403665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22448.

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 213403665 is about 14608.3423084209. The cubic root of 213403665 is about 597.5862891315.

Adding to 213403665 its reverse (566304312), we get a palindrome (779707977).

The spelling of 213403665 in words is "two hundred thirteen million, four hundred three thousand, six hundred sixty-five".