71239440 has 40 divisors (see below), whose sum is σ = 220843008. Its totient is φ = 18997120.

The previous prime is 71239411. The next prime is 71239453. The reversal of 71239440 is 4493217.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 71239398 and 71239407.

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 7 ways as a sum of consecutive naturals, for example, 148176 + ... + 148655.

Almost surely, 2^71239440 is an apocalyptic number.

It is an amenable number.

71239440 is an abundant number, since it is smaller than the sum of its proper divisors (149603568).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71239440 is a wasteful number, since it uses less digits than its factorization.

71239440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296847 (or 296841 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 71239440 is about 8440.3459644733. The cubic root of 71239440 is about 414.5467350054.

The spelling of 71239440 in words is "seventy-one million, two hundred thirty-nine thousand, four hundred forty".