71611540 has 192 divisors, whose sum is σ = 208857600. Its totient is φ = 20321280.

The previous prime is 71611451. The next prime is 71611567. The reversal of 71611540 is 4511617.

It is a happy number.

It is a super-2 number, since 2×71611540² = 10256425322343200, which 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 63 ways as a sum of consecutive naturals, for example, 980944 + ... + 981016.

It is an arithmetic number, because the mean of its divisors is an integer number (1087800).

Almost surely, 2^71611540 is an apocalyptic number.

71611540 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 71611540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104428800).

71611540 is an abundant number, since it is smaller than the sum of its proper divisors (137246060).

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

71611540 is a wasteful number, since it uses less digits than its factorization.

71611540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 111 counting only the distinct ones).

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

The square root of 71611540 is about 8462.3601908687. The cubic root of 71611540 is about 415.2672396897.

The spelling of 71611540 in words is "seventy-one million, six hundred eleven thousand, five hundred forty".