71089921 has 4 divisors (see below), whose sum is σ = 81245632. Its totient is φ = 60934212.

The previous prime is 71089877. The next prime is 71089927. The reversal of 71089921 is 12998017.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12998017 = 877 ⋅14821.

It is a cyclic number.

It is not a de Polignac number, because 71089921 - 2²⁵ = 37535489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71089927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5077845 + ... + 5077858.

It is an arithmetic number, because the mean of its divisors is an integer number (20311408).

Almost surely, 2^71089921 is an apocalyptic number.

It is an amenable number.

71089921 is a deficient number, since it is larger than the sum of its proper divisors (10155711).

71089921 is a wasteful number, since it uses less digits than its factorization.

71089921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10155710.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 71089921 is about 8431.4839144720. The cubic root of 71089921 is about 414.2565117460.

It can be divided in two parts, 71089 and 921, that added together give a triangular number (72010 = T₃₇₉).

The spelling of 71089921 in words is "seventy-one million, eighty-nine thousand, nine hundred twenty-one".