71705139 has 32 divisors (see below), whose sum is σ = 111421440. Its totient is φ = 40588800.

The previous prime is 71705129. The next prime is 71705143. The reversal of 71705139 is 93150717.

It is not a de Polignac number, because 71705139 - 2¹² = 71701043 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (71705129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28459 + ... + 30875.

It is an arithmetic number, because the mean of its divisors is an integer number (3481920).

Almost surely, 2^71705139 is an apocalyptic number.

71705139 is a deficient number, since it is larger than the sum of its proper divisors (39716301).

71705139 is a wasteful number, since it uses less digits than its factorization.

71705139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2491.

The product of its (nonzero) digits is 6615, while the sum is 33.

The square root of 71705139 is about 8467.8886978987. Note that the first 3 decimals coincide. The cubic root of 71705139 is about 415.4480842687.

The spelling of 71705139 in words is "seventy-one million, seven hundred five thousand, one hundred thirty-nine".