71257861 has 4 divisors (see below), whose sum is σ = 71276800. Its totient is φ = 71238924.

The previous prime is 71257817. The next prime is 71257873. The reversal of 71257861 is 16875217.

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: 16875217 = 197 ⋅85661.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71257861 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71257861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71257891) 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, 1701 + ... + 12058.

It is an arithmetic number, because the mean of its divisors is an integer number (17819200).

Almost surely, 2^71257861 is an apocalyptic number.

It is an amenable number.

71257861 is a deficient number, since it is larger than the sum of its proper divisors (18939).

71257861 is a wasteful number, since it uses less digits than its factorization.

71257861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18938.

The product of its digits is 23520, while the sum is 37.

The square root of 71257861 is about 8441.4371406769. The cubic root of 71257861 is about 414.5824629079.

The spelling of 71257861 in words is "seventy-one million, two hundred fifty-seven thousand, eight hundred sixty-one".