619199981 has 2 divisors, whose sum is σ = 619199982. Its totient is φ = 619199980.

The previous prime is 619199953. The next prime is 619200013. The reversal of 619199981 is 189991916.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 398202025 + 220997956 = 19955^2 + 14866^2 .

It is a cyclic number.

It is not a de Polignac number, because 619199981 - 2¹⁴ = 619183597 is a prime.

It is a super-2 number, since 2×619199981² = 766817232940800722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (619199941) 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, 309599990 + 309599991.

It is an arithmetic number, because the mean of its divisors is an integer number (309599991).

Almost surely, 2^619199981 is an apocalyptic number.

It is an amenable number.

619199981 is a deficient number, since it is larger than the sum of its proper divisors (1).

619199981 is an equidigital number, since it uses as much as digits as its factorization.

619199981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 53.

The square root of 619199981 is about 24883.7292422177. The cubic root of 619199981 is about 852.3349782490.

The spelling of 619199981 in words is "six hundred nineteen million, one hundred ninety-nine thousand, nine hundred eighty-one".