213685657 has 4 divisors (see below), whose sum is σ = 214143696. Its totient is φ = 213227620.

The previous prime is 213685651. The next prime is 213685691. The reversal of 213685657 is 756586312.

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 a cyclic number.

It is not a de Polignac number, because 213685657 - 2³ = 213685649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213685651) 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, 228319 + ... + 229252.

It is an arithmetic number, because the mean of its divisors is an integer number (53535924).

Almost surely, 2^213685657 is an apocalyptic number.

It is an amenable number.

213685657 is a deficient number, since it is larger than the sum of its proper divisors (458039).

213685657 is an equidigital number, since it uses as much as digits as its factorization.

213685657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458038.

The product of its digits is 302400, while the sum is 43.

The square root of 213685657 is about 14617.9908674209. The cubic root of 213685657 is about 597.8493904894.

The spelling of 213685657 in words is "two hundred thirteen million, six hundred eighty-five thousand, six hundred fifty-seven".