213545309 has 2 divisors, whose sum is σ = 213545310. Its totient is φ = 213545308.

The previous prime is 213545303. The next prime is 213545359. The reversal of 213545309 is 903545312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130462084 + 83083225 = 11422^2 + 9115^2 .

It is a cyclic number.

It is not a de Polignac number, because 213545309 - 2⁸ = 213545053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213545303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106772654 + 106772655.

It is an arithmetic number, because the mean of its divisors is an integer number (106772655).

Almost surely, 2^213545309 is an apocalyptic number.

It is an amenable number.

213545309 is a deficient number, since it is larger than the sum of its proper divisors (1).

213545309 is an equidigital number, since it uses as much as digits as its factorization.

213545309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16200, while the sum is 32.

The square root of 213545309 is about 14613.1895560141. The cubic root of 213545309 is about 597.7184733530.

The spelling of 213545309 in words is "two hundred thirteen million, five hundred forty-five thousand, three hundred nine".