71389521 has 18 divisors (see below), whose sum is σ = 119954562. Its totient is φ = 40793760.

The previous prime is 71389519. The next prime is 71389531. The reversal of 71389521 is 12598317.

It can be written as a sum of positive squares in only one way, i.e., 35820225 + 35569296 = 5985^2 + 5964^2 .

It is not a de Polignac number, because 71389521 - 2¹ = 71389519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71389501) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 80500 + ... + 81381.

Almost surely, 2^71389521 is an apocalyptic number.

It is an amenable number.

71389521 is a deficient number, since it is larger than the sum of its proper divisors (48565041).

71389521 is a wasteful number, since it uses less digits than its factorization.

71389521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161901 (or 161891 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 71389521 is about 8449.2319769314. The cubic root of 71389521 is about 414.8376410423.

The spelling of 71389521 in words is "seventy-one million, three hundred eighty-nine thousand, five hundred twenty-one".