1198601981 has 2 divisors, whose sum is σ = 1198601982. Its totient is φ = 1198601980.

The previous prime is 1198601959. The next prime is 1198602007. The reversal of 1198601981 is 1891068911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1194048025 + 4553956 = 34555^2 + 2134^2 .

It is an emirp because it is prime and its reverse (1891068911) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1861098611 and 1168901681.

It is a cyclic number.

It is not a de Polignac number, because 1198601981 - 2⁶ = 1198601917 is a prime.

It is a super-2 number, since 2×1198601981² = 2873293417714248722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1198601941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 599300990 + 599300991.

It is an arithmetic number, because the mean of its divisors is an integer number (599300991).

Almost surely, 2^1198601981 is an apocalyptic number.

It is an amenable number.

1198601981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1198601981 is an equidigital number, since it uses as much as digits as its factorization.

1198601981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 44.

The square root of 1198601981 is about 34620.8316046856. The cubic root of 1198601981 is about 1062.2457374697.

The spelling of 1198601981 in words is "one billion, one hundred ninety-eight million, six hundred one thousand, nine hundred eighty-one".