213555541 has 2 divisors, whose sum is σ = 213555542. Its totient is φ = 213555540.

The previous prime is 213555499. The next prime is 213555557. The reversal of 213555541 is 145555312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117809316 + 95746225 = 10854^2 + 9785^2 .

It is a cyclic number.

It is not a de Polignac number, because 213555541 - 2⁹ = 213555029 is a prime.

It is a nialpdrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213555341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106777770 + 106777771.

It is an arithmetic number, because the mean of its divisors is an integer number (106777771).

Almost surely, 2^213555541 is an apocalyptic number.

It is an amenable number.

213555541 is a deficient number, since it is larger than the sum of its proper divisors (1).

213555541 is an equidigital number, since it uses as much as digits as its factorization.

213555541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15000, while the sum is 31.

The square root of 213555541 is about 14613.5396465059. The cubic root of 213555541 is about 597.7280197389.

It can be divided in two parts, 21355 and 5541, that added together give a square (26896 = 164²).

The spelling of 213555541 in words is "two hundred thirteen million, five hundred fifty-five thousand, five hundred forty-one".