71561140 has 24 divisors (see below), whose sum is σ = 171747072. Its totient is φ = 24535200.

The previous prime is 71561131. The next prime is 71561167. The reversal of 71561140 is 4116517.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255436 + ... + 255715.

It is an arithmetic number, because the mean of its divisors is an integer number (7156128).

Almost surely, 2^71561140 is an apocalyptic number.

71561140 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

71561140 is an abundant number, since it is smaller than the sum of its proper divisors (100185932).

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

71561140 is a wasteful number, since it uses less digits than its factorization.

71561140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511167 (or 511165 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 71561140 is about 8459.3817741015. The cubic root of 71561140 is about 415.1697955216.

Adding to 71561140 its reverse (4116517), we get a palindrome (75677657).

The spelling of 71561140 in words is "seventy-one million, five hundred sixty-one thousand, one hundred forty".