561541997 has 2 divisors, whose sum is σ = 561541998. Its totient is φ = 561541996.

The previous prime is 561541991. The next prime is 561542063. The reversal of 561541997 is 799145165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 373687561 + 187854436 = 19331^2 + 13706^2 .

It is a cyclic number.

It is not a de Polignac number, because 561541997 - 2¹² = 561537901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561541991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280770998 + 280770999.

It is an arithmetic number, because the mean of its divisors is an integer number (280770999).

Almost surely, 2^561541997 is an apocalyptic number.

It is an amenable number.

561541997 is a deficient number, since it is larger than the sum of its proper divisors (1).

561541997 is an equidigital number, since it uses as much as digits as its factorization.

561541997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 340200, while the sum is 47.

The square root of 561541997 is about 23696.8773681260. The cubic root of 561541997 is about 825.0129153779.

The spelling of 561541997 in words is "five hundred sixty-one million, five hundred forty-one thousand, nine hundred ninety-seven".