71242240 has 80 divisors (see below), whose sum is σ = 180972792. Its totient is φ = 26804224.

The previous prime is 71242231. The next prime is 71242261. The reversal of 71242240 is 4224217.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 47114496 + 24127744 = 6864^2 + 4912^2 .

It is a tau number, because it is divible by the number of its divisors (80).

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, 42702 + ... + 44338.

Almost surely, 2^71242240 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 71242240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90486396).

71242240 is an abundant number, since it is smaller than the sum of its proper divisors (109730552).

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

71242240 is a wasteful number, since it uses less digits than its factorization.

71242240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1677 (or 1661 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 71242240 is about 8440.5118328215. The cubic root of 71242240 is about 414.5521660590.

Adding to 71242240 its reverse (4224217), we get a palindrome (75466457).

The spelling of 71242240 in words is "seventy-one million, two hundred forty-two thousand, two hundred forty".