71438640 has 160 divisors (see below), whose sum is σ = 272649216. Its totient is φ = 15068160.

The previous prime is 71438617. The next prime is 71438669. The reversal of 71438640 is 4683417.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20205 + ... + 23475.

Almost surely, 2^71438640 is an apocalyptic number.

71438640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71438640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136324608).

71438640 is an abundant number, since it is smaller than the sum of its proper divisors (201210576).

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

71438640 is a wasteful number, since it uses less digits than its factorization.

71438640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3307 (or 3301 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 71438640 is about 8452.1381910142. The cubic root of 71438640 is about 414.9327611585.

The spelling of 71438640 in words is "seventy-one million, four hundred thirty-eight thousand, six hundred forty".