71321553 has 10 divisors (see below), whose sum is σ = 106542194. Its totient is φ = 47547648.

The previous prime is 71321543. The next prime is 71321561. The reversal of 71321553 is 35512317.

It can be written as a sum of positive squares in only one way, i.e., 56205009 + 15116544 = 7497^2 + 3888^2 .

It is not a de Polignac number, because 71321553 - 2⁵ = 71321521 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71321543) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 440176 + ... + 440337.

Almost surely, 2^71321553 is an apocalyptic number.

It is an amenable number.

71321553 is a deficient number, since it is larger than the sum of its proper divisors (35220641).

71321553 is an equidigital number, since it uses as much as digits as its factorization.

71321553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880525 (or 880516 counting only the distinct ones).

The product of its digits is 3150, while the sum is 27.

The square root of 71321553 is about 8445.2088784115. The cubic root of 71321553 is about 414.7059474023.

The spelling of 71321553 in words is "seventy-one million, three hundred twenty-one thousand, five hundred fifty-three".