71801920 has 56 divisors (see below), whose sum is σ = 172099224. Its totient is φ = 28532736.

The previous prime is 71801903. The next prime is 71801927. The reversal of 71801920 is 2910817.

It can be written as a sum of positive squares in 4 ways, for example, as 45914176 + 25887744 = 6776^2 + 5088^2 .

It is not an unprimeable number, because it can be changed into a prime (71801927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54712 + ... + 56008.

Almost surely, 2^71801920 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 71801920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86049612).

71801920 is an abundant number, since it is smaller than the sum of its proper divisors (100297304).

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

71801920 is a wasteful number, since it uses less digits than its factorization.

71801920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1487 (or 1477 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 71801920 is about 8473.6013595165. The cubic root of 71801920 is about 415.6349114413.

The spelling of 71801920 in words is "seventy-one million, eight hundred one thousand, nine hundred twenty".