71220565 has 16 divisors (see below), whose sum is σ = 97454448. Its totient is φ = 49499136.

The previous prime is 71220563. The next prime is 71220587. The reversal of 71220565 is 56502217.

It can be written as a sum of positive squares in 8 ways, for example, as 16208676 + 55011889 = 4026^2 + 7417^2 .

It is a cyclic number.

It is not a de Polignac number, because 71220565 - 2¹ = 71220563 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71220563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31122 + ... + 33331.

It is an arithmetic number, because the mean of its divisors is an integer number (6090903).

Almost surely, 2^71220565 is an apocalyptic number.

It is an amenable number.

71220565 is a deficient number, since it is larger than the sum of its proper divisors (26233883).

71220565 is a wasteful number, since it uses less digits than its factorization.

71220565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64488.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 71220565 is about 8439.2277490301. The cubic root of 71220565 is about 414.5101201716.

The spelling of 71220565 in words is "seventy-one million, two hundred twenty thousand, five hundred sixty-five".