71907840 has 120 divisors (see below), whose sum is σ = 249116868. Its totient is φ = 19169280.

The previous prime is 71907827. The next prime is 71907863. The reversal of 71907840 is 4870917.

It can be written as a sum of positive squares in 2 ways, for example, as 58247424 + 13660416 = 7632^2 + 3696^2 .

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

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 71907795 and 71907804.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21480 + ... + 24600.

Almost surely, 2^71907840 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 71907840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124558434).

71907840 is an abundant number, since it is smaller than the sum of its proper divisors (177209028).

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

71907840 is a wasteful number, since it uses less digits than its factorization.

71907840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3150 (or 3131 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 71907840 is about 8479.8490552604. The cubic root of 71907840 is about 415.8391883367.

The spelling of 71907840 in words is "seventy-one million, nine hundred seven thousand, eight hundred forty".