71977860 has 72 divisors (see below), whose sum is σ = 220835160. Its totient is φ = 18974208.

The previous prime is 71977859. The next prime is 71977901. The reversal of 71977860 is 6877917.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17690436 + 54287424 = 4206^2 + 7368^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13774 + ... + 18266.

It is an arithmetic number, because the mean of its divisors is an integer number (3067155).

Almost surely, 2^71977860 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 71977860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110417580).

71977860 is an abundant number, since it is smaller than the sum of its proper divisors (148857300).

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

71977860 is a wasteful number, since it uses less digits than its factorization.

71977860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4597 (or 4592 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 45.

The square root of 71977860 is about 8483.9766619198. The cubic root of 71977860 is about 415.9741185205.

The spelling of 71977860 in words is "seventy-one million, nine hundred seventy-seven thousand, eight hundred sixty".