71556540 has 96 divisors (see below), whose sum is σ = 220147200. Its totient is φ = 17222400.

The previous prime is 71556539. The next prime is 71556547. The reversal of 71556540 is 4565517.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71556547) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 119161 + ... + 119759.

It is an arithmetic number, because the mean of its divisors is an integer number (2293200).

Almost surely, 2^71556540 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 71556540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110073600).

71556540 is an abundant number, since it is smaller than the sum of its proper divisors (148590660).

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

71556540 is a wasteful number, since it uses less digits than its factorization.

71556540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803 (or 801 counting only the distinct ones).

The product of its (nonzero) digits is 21000, while the sum is 33.

The square root of 71556540 is about 8459.1098822512. The cubic root of 71556540 is about 415.1608995296.

It can be divided in two parts, 7155 and 6540, that added together give a triangular number (13695 = T₁₆₅).

The spelling of 71556540 in words is "seventy-one million, five hundred fifty-six thousand, five hundred forty".