71257640 has 64 divisors (see below), whose sum is σ = 169516800. Its totient is φ = 26914048.

The previous prime is 71257633. The next prime is 71257679. The reversal of 71257640 is 4675217.

It is a junction number, because it is equal to n+sod(n) for n = 71257597 and 71257606.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53867 + ... + 55173.

It is an arithmetic number, because the mean of its divisors is an integer number (2648700).

Almost surely, 2^71257640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71257640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84758400).

71257640 is an abundant number, since it is smaller than the sum of its proper divisors (98259160).

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

71257640 is a wasteful number, since it uses less digits than its factorization.

71257640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1394 (or 1390 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 71257640 is about 8441.4240504787. The cubic root of 71257640 is about 414.5820343104.

The spelling of 71257640 in words is "seventy-one million, two hundred fifty-seven thousand, six hundred forty".