1981523959 has 2 divisors, whose sum is σ = 1981523960. Its totient is φ = 1981523958.

The previous prime is 1981523923. The next prime is 1981523969. The reversal of 1981523959 is 9593251891.

It is a strong prime.

It is an emirp because it is prime and its reverse (9593251891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1981523959 - 2¹¹ = 1981521911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1981523969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990761979 + 990761980.

It is an arithmetic number, because the mean of its divisors is an integer number (990761980).

Almost surely, 2^1981523959 is an apocalyptic number.

1981523959 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981523959 is an equidigital number, since it uses as much as digits as its factorization.

1981523959 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 874800, while the sum is 52.

The square root of 1981523959 is about 44514.3118446191. The cubic root of 1981523959 is about 1256.0293157096.

The spelling of 1981523959 in words is "one billion, nine hundred eighty-one million, five hundred twenty-three thousand, nine hundred fifty-nine".