71851521 has 64 divisors (see below), whose sum is σ = 122961920. Its totient is φ = 36391680.

The previous prime is 71851519. The next prime is 71851529. The reversal of 71851521 is 12515817.

It is not a de Polignac number, because 71851521 - 2¹ = 71851519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71851529) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 457575 + ... + 457731.

It is an arithmetic number, because the mean of its divisors is an integer number (1921280).

Almost surely, 2^71851521 is an apocalyptic number.

It is an amenable number.

71851521 is a deficient number, since it is larger than the sum of its proper divisors (51110399).

71851521 is a wasteful number, since it uses less digits than its factorization.

71851521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254.

The product of its digits is 2800, while the sum is 30.

The square root of 71851521 is about 8476.5276499284. The cubic root of 71851521 is about 415.7305967279.

The spelling of 71851521 in words is "seventy-one million, eight hundred fifty-one thousand, five hundred twenty-one".