561398555 has 8 divisors (see below), whose sum is σ = 684722544. Its totient is φ = 441756000.

The previous prime is 561398533. The next prime is 561398557. The reversal of 561398555 is 555893165.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-561398555 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561398557) 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, 920021 + ... + 920630.

It is an arithmetic number, because the mean of its divisors is an integer number (85590318).

Almost surely, 2^561398555 is an apocalyptic number.

561398555 is a deficient number, since it is larger than the sum of its proper divisors (123323989).

561398555 is a wasteful number, since it uses less digits than its factorization.

561398555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1840717.

The product of its digits is 810000, while the sum is 47.

The square root of 561398555 is about 23693.8505735138. The cubic root of 561398555 is about 824.9426614573.

The spelling of 561398555 in words is "five hundred sixty-one million, three hundred ninety-eight thousand, five hundred fifty-five".