71205421 has 4 divisors (see below), whose sum is σ = 81377632. Its totient is φ = 61033212.

The previous prime is 71205371. The next prime is 71205457. The reversal of 71205421 is 12450217.

It is a happy number.

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: 12450217 = 13 ⋅957709.

It is a cyclic number.

It is not a de Polignac number, because 71205421 - 2¹³ = 71197229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 71205392 and 71205401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71205221) 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, 5086095 + ... + 5086108.

It is an arithmetic number, because the mean of its divisors is an integer number (20344408).

Almost surely, 2^71205421 is an apocalyptic number.

It is an amenable number.

71205421 is a deficient number, since it is larger than the sum of its proper divisors (10172211).

71205421 is a wasteful number, since it uses less digits than its factorization.

71205421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10172210.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 71205421 is about 8438.3304628345. The cubic root of 71205421 is about 414.4807382731.

Adding to 71205421 its reverse (12450217), we get a palindrome (83655638).

The spelling of 71205421 in words is "seventy-one million, two hundred five thousand, four hundred twenty-one".