561858949957 has 2 divisors, whose sum is σ = 561858949958. Its totient is φ = 561858949956.

The previous prime is 561858949943. The next prime is 561858950021. The reversal of 561858949957 is 759949858165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 306172982241 + 255685967716 = 553329^2 + 505654^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561858949957 is a prime.

It is a super-3 number, since 3×561858949957³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561858941957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280929474978 + 280929474979.

It is an arithmetic number, because the mean of its divisors is an integer number (280929474979).

Almost surely, 2^561858949957 is an apocalyptic number.

It is an amenable number.

561858949957 is a deficient number, since it is larger than the sum of its proper divisors (1).

561858949957 is an equidigital number, since it uses as much as digits as its factorization.

561858949957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776000, while the sum is 76.

The spelling of 561858949957 in words is "five hundred sixty-one billion, eight hundred fifty-eight million, nine hundred forty-nine thousand, nine hundred fifty-seven".