199981248557 has 2 divisors, whose sum is σ = 199981248558. Its totient is φ = 199981248556.

The previous prime is 199981248497. The next prime is 199981248559. The reversal of 199981248557 is 755842189991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169475482276 + 30505766281 = 411674^2 + 174659^2 .

It is a cyclic number.

It is not a de Polignac number, because 199981248557 - 2³⁴ = 182801379373 is a prime.

It is a super-2 number, since 2×199981248557² (a number of 23 digits) contains 22 as substring.

Together with 199981248559, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199981248559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99990624278 + 99990624279.

It is an arithmetic number, because the mean of its divisors is an integer number (99990624279).

Almost surely, 2^199981248557 is an apocalyptic number.

It is an amenable number.

199981248557 is a deficient number, since it is larger than the sum of its proper divisors (1).

199981248557 is an equidigital number, since it uses as much as digits as its factorization.

199981248557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65318400, while the sum is 68.

The spelling of 199981248557 in words is "one hundred ninety-nine billion, nine hundred eighty-one million, two hundred forty-eight thousand, five hundred fifty-seven".