71028121 has 4 divisors (see below), whose sum is σ = 71044992. Its totient is φ = 71011252.

The previous prime is 71028119. The next prime is 71028169. The reversal of 71028121 is 12182017.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12182017 = 719 ⋅16943.

It is a cyclic number.

It is not a de Polignac number, because 71028121 - 2¹ = 71028119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71028092 and 71028101.

It is not an unprimeable number, because it can be changed into a prime (71028101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3696 + ... + 12478.

It is an arithmetic number, because the mean of its divisors is an integer number (17761248).

Almost surely, 2^71028121 is an apocalyptic number.

It is an amenable number.

71028121 is a deficient number, since it is larger than the sum of its proper divisors (16871).

71028121 is an equidigital number, since it uses as much as digits as its factorization.

71028121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16870.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 71028121 is about 8427.8182823314. The cubic root of 71028121 is about 414.1364362409.

The spelling of 71028121 in words is "seventy-one million, twenty-eight thousand, one hundred twenty-one".