71381520 has 160 divisors (see below), whose sum is σ = 281053440. Its totient is φ = 16312320.

The previous prime is 71381509. The next prime is 71381617. The reversal of 71381520 is 2518317.

71381520 is a `hidden beast` number, since 7 + 138 + 1 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 12760 + ... + 17480.

It is an arithmetic number, because the mean of its divisors is an integer number (1756584).

Almost surely, 2^71381520 is an apocalyptic number.

71381520 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 71381520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140526720).

71381520 is an abundant number, since it is smaller than the sum of its proper divisors (209671920).

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

71381520 is a wasteful number, since it uses less digits than its factorization.

71381520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4750 (or 4738 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 71381520 is about 8448.7584886775. The cubic root of 71381520 is about 414.8221427828.

Adding to 71381520 its reverse (2518317), we get a palindrome (73899837).

The spelling of 71381520 in words is "seventy-one million, three hundred eighty-one thousand, five hundred twenty".