71275621 has 4 divisors (see below), whose sum is σ = 71293644. Its totient is φ = 71257600.

The previous prime is 71275613. The next prime is 71275627. The reversal of 71275621 is 12657217.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24147396 + 47128225 = 4914^2 + 6865^2 .

It is a cyclic number.

It is not a de Polignac number, because 71275621 - 2³ = 71275613 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71275627) 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, 220 + ... + 11941.

It is an arithmetic number, because the mean of its divisors is an integer number (17823411).

Almost surely, 2^71275621 is an apocalyptic number.

It is an amenable number.

71275621 is a deficient number, since it is larger than the sum of its proper divisors (18023).

71275621 is a wasteful number, since it uses less digits than its factorization.

71275621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18022.

The product of its digits is 5880, while the sum is 31.

The square root of 71275621 is about 8442.4890287166. The cubic root of 71275621 is about 414.6169029581.

The spelling of 71275621 in words is "seventy-one million, two hundred seventy-five thousand, six hundred twenty-one".