71220581 has 4 divisors (see below), whose sum is σ = 74317152. Its totient is φ = 68124012.

The previous prime is 71220563. The next prime is 71220587. The reversal of 71220581 is 18502217.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18502217 = 2293 ⋅8069.

It is a cyclic number.

It is not a de Polignac number, because 71220581 - 2¹⁰ = 71219557 is a prime.

It is a super-2 number, since 2×71220581² = 10144742315955122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71220581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71220587) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1548251 + ... + 1548296.

It is an arithmetic number, because the mean of its divisors is an integer number (18579288).

Almost surely, 2^71220581 is an apocalyptic number.

It is an amenable number.

71220581 is a deficient number, since it is larger than the sum of its proper divisors (3096571).

71220581 is a wasteful number, since it uses less digits than its factorization.

71220581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3096570.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 71220581 is about 8439.2286969841. The cubic root of 71220581 is about 414.5101512121.

Adding to 71220581 its reverse (18502217), we get a palindrome (89722798).

The spelling of 71220581 in words is "seventy-one million, two hundred twenty thousand, five hundred eighty-one".