71611221 has 16 divisors (see below), whose sum is σ = 106380288. Its totient is φ = 42476400.

The previous prime is 71611219. The next prime is 71611223. The reversal of 71611221 is 12211617.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (71611219) and next prime (71611223).

It is not a de Polignac number, because 71611221 - 2¹ = 71611219 is a prime.

It is a super-2 number, since 2×71611221² = 10256333946221682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71611223) 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, 21535 + ... + 24636.

It is an arithmetic number, because the mean of its divisors is an integer number (6648768).

Almost surely, 2^71611221 is an apocalyptic number.

It is an amenable number.

71611221 is a deficient number, since it is larger than the sum of its proper divisors (34769067).

71611221 is a wasteful number, since it uses less digits than its factorization.

71611221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46232.

The product of its digits is 168, while the sum is 21.

The square root of 71611221 is about 8462.3413426782. The cubic root of 71611221 is about 415.2666230738.

Adding to 71611221 its reverse (12211617), we get a palindrome (83822838).

The spelling of 71611221 in words is "seventy-one million, six hundred eleven thousand, two hundred twenty-one".