213623 has 2 divisors, whose sum is σ = 213624. Its totient is φ = 213622.

The previous prime is 213613. The next prime is 213637. The reversal of 213623 is 326312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213623 is a prime.

It is a super-2 number, since 2×213623² = 91269572258, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106811 + 106812.

It is an arithmetic number, because the mean of its divisors is an integer number (106812).

2²¹³⁶²³ is an apocalyptic number.

213623 is a deficient number, since it is larger than the sum of its proper divisors (1).

213623 is an equidigital number, since it uses as much as digits as its factorization.

213623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 17.

The square root of 213623 is about 462.1936823454. The cubic root of 213623 is about 59.7790950892.

Adding to 213623 its reverse (326312), we get a palindrome (539935).

The spelling of 213623 in words is "two hundred thirteen thousand, six hundred twenty-three".