71552209 has 2 divisors, whose sum is σ = 71552210. Its totient is φ = 71552208.

The previous prime is 71552179. The next prime is 71552213. The reversal of 71552209 is 90225517.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43758225 + 27793984 = 6615^2 + 5272^2 .

It is an emirp because it is prime and its reverse (90225517) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71552209 - 2²³ = 63163601 is a prime.

It is a super-2 number, since 2×71552209² = 10239437225559362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71552009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35776104 + 35776105.

It is an arithmetic number, because the mean of its divisors is an integer number (35776105).

Almost surely, 2^71552209 is an apocalyptic number.

It is an amenable number.

71552209 is a deficient number, since it is larger than the sum of its proper divisors (1).

71552209 is an equidigital number, since it uses as much as digits as its factorization.

71552209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 71552209 is about 8458.8538821758. The cubic root of 71552209 is about 415.1525234113.

The spelling of 71552209 in words is "seventy-one million, five hundred fifty-two thousand, two hundred nine".