561287688218 has 4 divisors (see below), whose sum is σ = 841931532330. Its totient is φ = 280643844108.

The previous prime is 561287688217. The next prime is 561287688287. The reversal of 561287688218 is 812886782165.

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., 552365563369 + 8922124849 = 743213^2 + 94457^2 .

It is not an unprimeable number, because it can be changed into a prime (561287688217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140321922053 + ... + 140321922056.

Almost surely, 2^561287688218 is an apocalyptic number.

561287688218 is a deficient number, since it is larger than the sum of its proper divisors (280643844112).

561287688218 is a wasteful number, since it uses less digits than its factorization.

561287688218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280643844111.

The product of its digits is 20643840, while the sum is 62.

The spelling of 561287688218 in words is "five hundred sixty-one billion, two hundred eighty-seven million, six hundred eighty-eight thousand, two hundred eighteen".