1919539148581 has 2 divisors, whose sum is σ = 1919539148582. Its totient is φ = 1919539148580.

The previous prime is 1919539148561. The next prime is 1919539148591. The reversal of 1919539148581 is 1858419359191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1627561026081 + 291978122500 = 1275759^2 + 540350^2 .

It is a cyclic number.

It is not a de Polignac number, because 1919539148581 - 2¹¹ = 1919539146533 is a prime.

It is a super-2 number, since 2×1919539148581² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1919539148561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959769574290 + 959769574291.

It is an arithmetic number, because the mean of its divisors is an integer number (959769574291).

Almost surely, 2^{1919539148581} is an apocalyptic number.

It is an amenable number.

1919539148581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919539148581 is an equidigital number, since it uses as much as digits as its factorization.

1919539148581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13996800, while the sum is 64.

The spelling of 1919539148581 in words is "one trillion, nine hundred nineteen billion, five hundred thirty-nine million, one hundred forty-eight thousand, five hundred eighty-one".