213381691 has 4 divisors (see below), whose sum is σ = 213614800. Its totient is φ = 213148584.

The previous prime is 213381689. The next prime is 213381697. The reversal of 213381691 is 196183312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 213381691 - 2¹ = 213381689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213381697) 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, 115176 + ... + 117013.

It is an arithmetic number, because the mean of its divisors is an integer number (53403700).

Almost surely, 2^213381691 is an apocalyptic number.

213381691 is a deficient number, since it is larger than the sum of its proper divisors (233109).

213381691 is an equidigital number, since it uses as much as digits as its factorization.

213381691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233108.

The product of its digits is 7776, while the sum is 34.

The square root of 213381691 is about 14607.5901845582. The cubic root of 213381691 is about 597.5657774377.

The spelling of 213381691 in words is "two hundred thirteen million, three hundred eighty-one thousand, six hundred ninety-one".