71977686 has 32 divisors (see below), whose sum is σ = 158675328. Its totient is φ = 21584640.

The previous prime is 71977679. The next prime is 71977687. The reversal of 71977686 is 68677917.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71977687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 781 + ... + 12023.

It is an arithmetic number, because the mean of its divisors is an integer number (4958604).

Almost surely, 2^71977686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71977686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79337664).

71977686 is an abundant number, since it is smaller than the sum of its proper divisors (86697642).

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

71977686 is a wasteful number, since it uses less digits than its factorization.

71977686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11356.

The product of its digits is 889056, while the sum is 51.

The square root of 71977686 is about 8483.9664072885. The cubic root of 71977686 is about 415.9737833269.

The spelling of 71977686 in words is "seventy-one million, nine hundred seventy-seven thousand, six hundred eighty-six".