1598611981 has 2 divisors, whose sum is σ = 1598611982. Its totient is φ = 1598611980.

The previous prime is 1598611939. The next prime is 1598611991. The reversal of 1598611981 is 1891168951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1549681956 + 48930025 = 39366^2 + 6995^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1598611981 is a prime.

It is a super-2 number, since 2×1598611981² = 5111120531593488722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1598611901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 799305990 + 799305991.

It is an arithmetic number, because the mean of its divisors is an integer number (799305991).

Almost surely, 2^1598611981 is an apocalyptic number.

It is an amenable number.

1598611981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1598611981 is an equidigital number, since it uses as much as digits as its factorization.

1598611981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 49.

The square root of 1598611981 is about 39982.6459979827. The cubic root of 1598611981 is about 1169.2687814211.

The spelling of 1598611981 in words is "one billion, five hundred ninety-eight million, six hundred eleven thousand, nine hundred eighty-one".