71521411 has 4 divisors (see below), whose sum is σ = 77023072. Its totient is φ = 66019752.

The previous prime is 71521399. The next prime is 71521423. The reversal of 71521411 is 11412517.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11412517 = 1279 ⋅8923.

It is an interprime number because it is at equal distance from previous prime (71521399) and next prime (71521423).

It is a cyclic number.

It is not a de Polignac number, because 71521411 - 2⁹ = 71520899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71522411) 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, 2750811 + ... + 2750836.

It is an arithmetic number, because the mean of its divisors is an integer number (19255768).

Almost surely, 2^71521411 is an apocalyptic number.

71521411 is a deficient number, since it is larger than the sum of its proper divisors (5501661).

71521411 is a wasteful number, since it uses less digits than its factorization.

71521411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5501660.

The product of its digits is 280, while the sum is 22.

The square root of 71521411 is about 8457.0332268473. The cubic root of 71521411 is about 415.0929505833.

Adding to 71521411 its reverse (11412517), we get a palindrome (82933928).

The spelling of 71521411 in words is "seventy-one million, five hundred twenty-one thousand, four hundred eleven".