71405021520 has 240 divisors, whose sum is σ = 274855800960. Its totient is φ = 16273714176.

The previous prime is 71405021491. The next prime is 71405021533. The reversal of 71405021520 is 2512050417.

71405021520 is a `hidden beast` number, since 7 + 1 + 4 + 0 + 502 + 152 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×71405021520² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1728466 + ... + 1769294.

It is an arithmetic number, because the mean of its divisors is an integer number (1145232504).

Almost surely, 2^71405021520 is an apocalyptic number.

71405021520 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 71405021520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137427900480).

71405021520 is an abundant number, since it is smaller than the sum of its proper divisors (203450779440).

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

71405021520 is a wasteful number, since it uses less digits than its factorization.

71405021520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41202 (or 41193 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

Adding to 71405021520 its reverse (2512050417), we get a palindrome (73917071937).

The spelling of 71405021520 in words is "seventy-one billion, four hundred five million, twenty-one thousand, five hundred twenty".