71521224 has 16 divisors (see below), whose sum is σ = 178803120. Its totient is φ = 23840400.

The previous prime is 71521217. The next prime is 71521249. The reversal of 71521224 is 42212517.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 2980051 = 71521224 / (7 + 1 + 5 + 2 + 1 + 2 + 2 + 4).

It is a junction number, because it is equal to n+sod(n) for n = 71521194 and 71521203.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1490002 + ... + 1490049.

It is an arithmetic number, because the mean of its divisors is an integer number (11175195).

Almost surely, 2^71521224 is an apocalyptic number.

It is an amenable number.

71521224 is an abundant number, since it is smaller than the sum of its proper divisors (107281896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71521224 is a wasteful number, since it uses less digits than its factorization.

71521224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980060 (or 2980056 counting only the distinct ones).

The product of its digits is 1120, while the sum is 24.

The square root of 71521224 is about 8457.0221709536. The cubic root of 71521224 is about 415.0925888154.

The spelling of 71521224 in words is "seventy-one million, five hundred twenty-one thousand, two hundred twenty-four".