72405071720 has 16 divisors (see below), whose sum is σ = 162911411460. Its totient is φ = 28962028672.

The previous prime is 72405071647. The next prime is 72405071723. The reversal of 72405071720 is 2717050427.

It can be written as a sum of positive squares in 2 ways, for example, as 72383597764 + 21473956 = 269042^2 + 4634^2 .

It is not an unprimeable number, because it can be changed into a prime (72405071723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 905063357 + ... + 905063436.

Almost surely, 2^72405071720 is an apocalyptic number.

It is an amenable number.

72405071720 is an abundant number, since it is smaller than the sum of its proper divisors (90506339740).

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

72405071720 is a wasteful number, since it uses less digits than its factorization.

72405071720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1810126804 (or 1810126800 counting only the distinct ones).

The product of its (nonzero) digits is 27440, while the sum is 35.

The spelling of 72405071720 in words is "seventy-two billion, four hundred five million, seventy-one thousand, seven hundred twenty".