71007840 has 120 divisors (see below), whose sum is σ = 250644240. Its totient is φ = 18931968.

The previous prime is 71007823. The next prime is 71007841. The reversal of 71007840 is 4870017.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×71007840² = 10084226682931200, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71007841) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10221 + ... + 15699.

It is an arithmetic number, because the mean of its divisors is an integer number (2088702).

Almost surely, 2^71007840 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 71007840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125322120).

71007840 is an abundant number, since it is smaller than the sum of its proper divisors (179636400).

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

71007840 is a wasteful number, since it uses less digits than its factorization.

71007840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5506 (or 5489 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 71007840 is about 8426.6149787444. The cubic root of 71007840 is about 414.0970157011.

Adding to 71007840 its reverse (4870017), we get a palindrome (75877857).

The spelling of 71007840 in words is "seventy-one million, seven thousand, eight hundred forty".