71521172 has 6 divisors (see below), whose sum is σ = 125162058. Its totient is φ = 35760584.

The previous prime is 71521147. The next prime is 71521189. The reversal of 71521172 is 27112517.

It can be written as a sum of positive squares in only one way, i.e., 69789316 + 1731856 = 8354^2 + 1316^2 .

It is a congruent number.

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 as a sum of consecutive naturals, namely, 8940143 + ... + 8940150.

It is an arithmetic number, because the mean of its divisors is an integer number (20860343).

Almost surely, 2^71521172 is an apocalyptic number.

It is an amenable number.

71521172 is a deficient number, since it is larger than the sum of its proper divisors (53640886).

71521172 is a wasteful number, since it uses less digits than its factorization.

71521172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17880297 (or 17880295 counting only the distinct ones).

The product of its digits is 980, while the sum is 26.

The square root of 71521172 is about 8457.0190965848. The cubic root of 71521172 is about 415.0924882168.

Adding to 71521172 its reverse (27112517), we get a palindrome (98633689).

The spelling of 71521172 in words is "seventy-one million, five hundred twenty-one thousand, one hundred seventy-two".