19981310390537 has 2 divisors, whose sum is σ = 19981310390538. Its totient is φ = 19981310390536.

The previous prime is 19981310390413. The next prime is 19981310390543. The reversal of 19981310390537 is 73509301318991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18555254071561 + 1426056318976 = 4307581^2 + 1194176^2 .

It is a cyclic number.

It is not a de Polignac number, because 19981310390537 - 2¹⁶ = 19981310325001 is a prime.

It is not a weakly prime, because it can be changed into another prime (19981310390137) 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, 9990655195268 + 9990655195269.

It is an arithmetic number, because the mean of its divisors is an integer number (9990655195269).

Almost surely, 2^{19981310390537} is an apocalyptic number.

It is an amenable number.

19981310390537 is a deficient number, since it is larger than the sum of its proper divisors (1).

19981310390537 is an equidigital number, since it uses as much as digits as its factorization.

19981310390537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5511240, while the sum is 59.

The spelling of 19981310390537 in words is "nineteen trillion, nine hundred eighty-one billion, three hundred ten million, three hundred ninety thousand, five hundred thirty-seven".