71987905 has 16 divisors (see below), whose sum is σ = 94647168. Its totient is φ = 52128000.

The previous prime is 71987887. The next prime is 71987957. The reversal of 71987905 is 50978917.

It is not a de Polignac number, because 71987905 - 2⁷ = 71987777 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10540 + ... + 15970.

It is an arithmetic number, because the mean of its divisors is an integer number (5915448).

Almost surely, 2^71987905 is an apocalyptic number.

It is an amenable number.

71987905 is a deficient number, since it is larger than the sum of its proper divisors (22659263).

71987905 is a wasteful number, since it uses less digits than its factorization.

71987905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5688.

The product of its (nonzero) digits is 158760, while the sum is 46.

The square root of 71987905 is about 8484.5686395951. The cubic root of 71987905 is about 415.9934682930.

The spelling of 71987905 in words is "seventy-one million, nine hundred eighty-seven thousand, nine hundred five".