561999397 has 2 divisors, whose sum is σ = 561999398. Its totient is φ = 561999396.

The previous prime is 561999371. The next prime is 561999407. The reversal of 561999397 is 793999165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 456505956 + 105493441 = 21366^2 + 10271^2 .

It is a cyclic number.

It is not a de Polignac number, because 561999397 - 2¹¹ = 561997349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561999337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280999698 + 280999699.

It is an arithmetic number, because the mean of its divisors is an integer number (280999699).

Almost surely, 2^561999397 is an apocalyptic number.

It is an amenable number.

561999397 is a deficient number, since it is larger than the sum of its proper divisors (1).

561999397 is an equidigital number, since it uses as much as digits as its factorization.

561999397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4133430, while the sum is 58.

The square root of 561999397 is about 23706.5264642461. The cubic root of 561999397 is about 825.2368573667.

The spelling of 561999397 in words is "five hundred sixty-one million, nine hundred ninety-nine thousand, three hundred ninety-seven".