1919539148561 has 2 divisors, whose sum is σ = 1919539148562. Its totient is φ = 1919539148560.

The previous prime is 1919539148497. The next prime is 1919539148581. The reversal of 1919539148561 is 1658419359191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1785056323600 + 134482824961 = 1336060^2 + 366719^2 .

It is a cyclic number.

It is not a de Polignac number, because 1919539148561 - 2⁶ = 1919539148497 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1919539148494 and 1919539148503.

It is not a weakly prime, because it can be changed into another prime (1919539148581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959769574280 + 959769574281.

It is an arithmetic number, because the mean of its divisors is an integer number (959769574281).

Almost surely, 2^{1919539148561} is an apocalyptic number.

It is an amenable number.

1919539148561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919539148561 is an equidigital number, since it uses as much as digits as its factorization.

1919539148561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10497600, while the sum is 62.

The spelling of 1919539148561 in words is "one trillion, nine hundred nineteen billion, five hundred thirty-nine million, one hundred forty-eight thousand, five hundred sixty-one".