8213547509 has 2 divisors, whose sum is σ = 8213547510. Its totient is φ = 8213547508.

The previous prime is 8213547499. The next prime is 8213547593. The reversal of 8213547509 is 9057453128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7196128900 + 1017418609 = 84830^2 + 31897^2 .

It is a cyclic number.

It is not a de Polignac number, because 8213547509 - 2⁸ = 8213547253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8213547509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8213547409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4106773754 + 4106773755.

It is an arithmetic number, because the mean of its divisors is an integer number (4106773755).

Almost surely, 2^8213547509 is an apocalyptic number.

It is an amenable number.

8213547509 is a deficient number, since it is larger than the sum of its proper divisors (1).

8213547509 is an equidigital number, since it uses as much as digits as its factorization.

8213547509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 302400, while the sum is 44.

The square root of 8213547509 is about 90628.6241151216. The cubic root of 8213547509 is about 2017.6395907811.

The spelling of 8213547509 in words is "eight billion, two hundred thirteen million, five hundred forty-seven thousand, five hundred nine".