561390257 has 4 divisors (see below), whose sum is σ = 571982580. Its totient is φ = 550797936.

The previous prime is 561390239. The next prime is 561390287. The reversal of 561390257 is 752093165.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 357928561 + 203461696 = 18919^2 + 14264^2 .

It is a cyclic number.

It is not a de Polignac number, because 561390257 - 2¹⁰ = 561389233 is a prime.

It is a super-3 number, since 3×561390257³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 561390257.

It is not an unprimeable number, because it can be changed into a prime (561390287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5296082 + ... + 5296187.

It is an arithmetic number, because the mean of its divisors is an integer number (142995645).

Almost surely, 2^561390257 is an apocalyptic number.

It is an amenable number.

561390257 is a deficient number, since it is larger than the sum of its proper divisors (10592323).

561390257 is a wasteful number, since it uses less digits than its factorization.

561390257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10592322.

The product of its (nonzero) digits is 56700, while the sum is 38.

The square root of 561390257 is about 23693.6754641402. The cubic root of 561390257 is about 824.9385969605.

The spelling of 561390257 in words is "five hundred sixty-one million, three hundred ninety thousand, two hundred fifty-seven".