581720520946 has 4 divisors (see below), whose sum is σ = 872580781422. Its totient is φ = 290860260472.

The previous prime is 581720520943. The next prime is 581720520959. The reversal of 581720520946 is 649025027185.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 488915600625 + 92804920321 = 699225^2 + 304639^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 581720520946.

It is not an unprimeable number, because it can be changed into a prime (581720520943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145430130235 + ... + 145430130238.

Almost surely, 2^581720520946 is an apocalyptic number.

581720520946 is a deficient number, since it is larger than the sum of its proper divisors (290860260476).

581720520946 is a wasteful number, since it uses less digits than its factorization.

581720520946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290860260475.

The product of its (nonzero) digits is 1209600, while the sum is 49.

The spelling of 581720520946 in words is "five hundred eighty-one billion, seven hundred twenty million, five hundred twenty thousand, nine hundred forty-six".